A method of using a finishing element and using organic lubricating films for finishing semiconductor wafers is described. The lubricants in the finishing element can be transferred to operative finishing interface and can form a self-assembling lubricating film. The organic lubricating film thickness can be controlled to improve finishing and reduce unwanted surface defects. Differential organic lubricating film methods are described to differentially finish semiconductor wafers. Planarization and localized finishing can be improved using differential lubricating boundary layer and organic lubricating film methods of finishing.
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41. A method of finishing a semiconductor wafer surface having a uniform region surface comprising the steps of:
providing a finishing surface; providing an organic lubricant between the finishing surface and the uniform region surface; and applying an operative finishing motion between the semiconductor wafer surface and the finishing surface forming an organic lubricating film of at most 10 molecules thick on the conductive region of the semiconductor wafer surface wherein: the operative finishing motion forms a friction in the interface between the conductive region on the semiconductor wafer surface and the finishing surface; and the organic lubricating film interacts with and self-assembles with the uniform region surface to reduce a coefficient of friction. 1. A method of finishing a semiconductor wafer having a semiconductor wafer surface comprising the steps of:
providing a finishing element finishing surface comprising a polymer; positioning the semiconductor wafer surface proximate to the finishing surface; providing an organic lubricant proximate to the surface of the semiconductor wafer surface; applying an operative finishing motion in an interface between the semiconductor wafer surface and the finishing element finishing surface; and wherein applying the operative finishing motion forms an organic lubricating film layer of at most 10 molecules thick which self-assembles with and adheres to the semiconductor wafer surface forming a heterogeneous lubrication on the semiconductor wafer surface during a finishing cycle time. 83. A method of finishing of a semiconductor wafer surface having a first uniform region surface and a second uniform region surface comprising the steps of:
providing a finishing element finishing surface; providing an organic lubricant to an interface between the finishing element finishing surface and the semiconductor wafer surface; and applying an operative finishing motion to the interface formed between the finishing element finishing surface and the first and second uniform region surfaces forming a marginal organic lubricating film on at least the first uniform region surface and wherein the operative finishing motion forms a friction in the interface between the semiconductor wafer surface and the finishing element finishing surface and the marginal organic lubricating film self-assembles with and adheres to at least the first uniform region; and controlling the marginal organic lubricating film by changing at least one control parameter in a manner that changes a coefficient of friction in at least the first uniform region in response to an in situ control signal during at least a portion of the finishing cycle time; and inducing differential tribochemical wear to at least a portion of the semiconductor wafer surface.
64. A method of finishing a semiconductor wafer surface having uniform regions, the method comprising the steps of:
providing an finishing element finishing surface; providing an organic lubricant to an interface between the semiconductor wafer surface and the finishing element finishing surface; and applying an operative finishing motion forming a marginal organic lubricating film on at least a portion of the semiconductor wafer surface and wherein the operative finishing motion forms a friction in the interface between the uniform regions of the semiconductor wafer surface and the finishing element finishing surface; self-assembling of a marginal organic lubricating film with the uniform regions of the semiconductor wafer surface during at least a portion of a finishing cycle time; sensing in situ finishing information with at least one operative sensor; and controlling the marginal organic lubricating film by changing at least one control parameter in a manner that changes a coefficient of friction in at least two different uniform regions of the interface between the semiconductor wafer surface and the finishing element finishing surface in response to an in situ control signal during at least the portion of the finishing cycle time.
28. A method of finishing of a semiconductor wafer surface having a first uniform region surface and a second uniform region surface comprising the steps of:
providing a finishing surface comprising at least in part an organic polymer; providing a control subsystem having a plurality of operative sensors, a controller, and a processor having access to look-up tables and historical performance; positioning the semiconductor wafer surface proximate to the finishing surface; providing an organic lubricant between the finishing surface and the first and second uniform region surfaces of the semiconductor wafer surface; applying an operative finishing motion in an interface comprising the finishing surface and the first and second uniform region surfaces forming a self-assembling organic lubricating film on at least the first uniform region surface; sensing progress of finishing information with the plurality of operative sensors; determining a change to at least one process control parameter using the progress of finishing information, the look-up tables, and the historical performance; and changing the at least one process control parameter in a manner that changes a coefficient of friction in at least one of the first and second uniform region surfaces during at least a portion of the finishing cycle time.
49. A method of finishing a semiconductor wafer having a semiconductor wafer surface and a tracking code comprising the steps of:
providing an finishing element finishing surface; providing an organic lubricant to an interface between the finishing element finishing surface and the semiconductor wafer surface; providing a control subsystem having a processor, a plurality of operative sensors, and a controller and wherein the processor has access to the tracking code, look-up tables, and a control logic consistent with the current manufacturing step; and applying an operative finishing motion to the interface between the finishing element finishing surface and the semiconductor wafer surface forming an organic lubricating film which adheres to at least a portion of the semiconductor wafer surface; sensing a first progress of finishing information with the plurality of operative sensors; determining a change to least one process control parameter at least in part using the progress of finishing information, the tracking code, the look-up tables, and the control logic consistent with the current manufacturing step; changing the at least one process control parameter; sensing a second progress of finishing information with the plurality of operative sensors after changing the at least one process control parameter; and storing at least in part the first progress of finishing information, the second progress of finishing information, the tracking code, and the control logic consistent with the current manufacturing step which was used.
84. A method of finishing a semiconductor wafer having a semiconductor wafer surface and a tracking code comprising the steps of:
providing a finishing element finishing surface; providing a finishing aid to an interface between the finishing element finishing surface and the semiconductor wafer surface and wherein the finishing aid is selected from the group consisting of a lubricating aid and a chemically reactive aid; providing a control subsystem having a processor, a plurality of operative sensors, and a controller and wherein the processor has access to the tracking code, look-up tables, and a control logic consistent with the current manufacturing step; and applying an operative finishing motion to the interface between the finishing element finishing surface and the semiconductor wafer surface forming a reaction between the finishing aid and the semiconductor wafer on a portion of the semiconductor wafer surface; sensing a first progress of finishing information with the plurality of operative sensors; determining a change to at least one process control parameter at least in part using the progress of finishing information, the tracking code, the look-up tables, and the control logic consistent with the current manufacturing step; changing the at least one process control parameter; sensing a second progress of finishing information with the plurality of operative sensors after changing the at least one process control parameter; and storing at least in part the first progress of finishing information, the second progress of finishing information, the tracking code, and the control logic consistent with the current manufacturing step which was used.
2. The method of finishing according to
3. The method of finishing according to
sensing the progress of finishing information with an operative sensor; determining a change to at least one process control parameter using an integrated circuit for processing information to evaluate the progress of finishing information; and controlling the at least one process control parameter.
4. The method of finishing according to
5. The method of finishing according to
6. The method of finishing according to
7. The method of finishing according to
sensing the progress of finishing information with an operative sensor; determining a change to at least one process control parameter using a processor having access to look-up tables and historical performance; and controlling the at least one process control parameter.
8. The method of finishing according to
9. The method of finishing according to
10. The method of finishing according to
11. The method of finishing according to
the semiconductor wafer has a plurality of metal layers and a tracking code; and wherein the method of finishing has a finishing cycle time; and during the finishing cycle time having the additional steps of: providing a control subsystem having an integrated circuit for processing information having access to the tracking code, look-up tables, and a control logic consistent with the current manufacturing step; sensing the progress of finishing information with an operative sensor; determining a change to at least one process control parameter using at least in part the progress of finishing information, the tracking code, the look-up tables, and the control logic consistent with the current manufacturing step; and controlling the at least one control parameter. 12. The method of finishing according to
13. The method of finishing according to
14. The method of finishing according to
using the stored information to determine a process control parameter for a subsequent finishing step; and controlling the process control parameter in a subsequent finishing step.
15. The method of finishing according to
16. The method of finishing according to
17. The method of finishing according to
18. The method of
providing a finishing composition free of abrasive particles proximate to the surface of the semiconductor wafer surface.
19. The method of
providing a finishing composition free of abrasive particles proximate to the surface of the semiconductor wafer surface; and wherein the finishing element finishing surface is free of inorganic abrasive particles. 20. The method of finishing according to
21. The method of
providing a finishing composition free of abrasive particles proximate to the surface of the semiconductor wafer surface.
22. The method of
providing a finishing composition free of abrasive particles proximate to the surface of the semiconductor wafer surface; and wherein the finishing element finishing surface is free of inorganic abrasive particles. 23. The method of finishing according to
24. The method of finishing according to
the semiconductor wafer surface comprises a heterogeneous semiconductor wafer surface having different compositions during the finishing cycle time; and having the additional step of: differentially lubricating the different compositions during the finishing cycle time. 25. The method of finishing according to
the finishing element finishing surface comprises a fixed abrasive finishing surface; and the semiconductor wafer surface comprises a heterogeneous semiconductor wafer surface having different compositions during the finishing cycle time; and having the additional step of: differentially lubricating the different compositions during the finishing cycle time. 26. The method of finishing according to
the finishing element finishing surface has inorganic abrasive particles; and the semiconductor wafer surface comprises a heterogeneous semiconductor wafer surface having different compositions during the finishing cycle time; and having the additional steps of: supplying a finishing composition free of abrasive particles to the interface between the semiconductor wafer surface and the finishing element finishing surface during the finishing cycle time; and differentially lubricating the different compositions during the finishing cycle time. 27. The method of finishing according to
providing a finishing composition which chemically reacts preferentially with a portion of the semiconductor wafer surface.
29. The method of finishing according to
30. The method of finishing according to
the semiconductor wafer has a plurality of metal layers and a tracking code; the method of finishing has a finishing cycle time; providing a control subsystem comprises providing a control subsystem having the processor having access to the tracking code, the historical performance, the look-up tables, and a control logic consistent with the current manufacturing step; sensing the progress of finishing comprises sensing the progress of finishing information with the plurality of operative sensors; determining a change for at least one process control parameter comprises determining a change for the at least one process control parameter using at least in part the progress of finishing information, the tracking code, the historical performance, the look-up tables, and the control logic consistent with the current manufacturing step; and changing the at least one control parameter comprises changing the at least one control parameter to change the finishing during the finishing cycle time.
31. The method of finishing according to
the semiconductor wafer has a plurality of metal layers and a tracking code; the method of finishing has a finishing cycle time; providing a control subsystem comprises providing a control subsystem having the processor having access to the tracking code, the historical performance, and the look-up tables; sensing the progress of finishing comprises sensing the progress of finishing information with the plurality of operative sensors; determining a change for at least one process control parameters comprises determining a change for at least two process control parameters using at least in part the progress of finishing information, the tracking code, the historical performance, and the look-up tables; and changing the at least one control parameter comprises changing the at least two control parameters to change the finishing of the semiconductor wafer during the finishing cycle time.
32. The method of finishing according to
33. The method of finishing according to
34. The method of finishing according to
35. The method of
providing a finishing composition free of abrasive particles between the semiconductor wafer surface and the finishing surface.
36. The method of
providing a finishing composition free of abrasive particles between the semiconductor wafer surface and the finishing surface; and wherein the finishing surface is free of inorganic abrasive particles. 37. The method of finishing according to
38. The method of finishing according to
39. The method of finishing according to
40. The method of finishing according to
42. The method of finishing according to
43. The method of finishing according to
44. The method of finishing according to
sensing the progress of finishing with an operative sensor; determining the change for at least two process control parameters using an integrated circuit for processing information; and changing the at least two control parameters during a finishing cycle time.
45. The method of finishing according to
the semiconductor wafer has a plurality of metal layers and a tracking code; and wherein the method of finishing has a finishing cycle time; and during the finishing cycle time having the additional steps of: providing a control subsystem having an integrated circuit for processing information having access to the tracking code, look-up tables, and a control logic consistent with the current manufacturing step; determining a change to at least one process control parameter using at least in part the progress of finishing information, the tracking code, the look-up tables, and the control logic consistent with the current manufacturing step; and storing information comprising at least in part the progress of finishing information, the tracking code, and the control logic consistent with the current manufacturing step which was used. 46. The method of finishing according to
47. The method of finishing according to
48. The method of finishing according to
using the stored information to determine a process control parameter for a subsequent finishing step; and controlling the process control parameter in a subsequent finishing step.
50. The method of finishing according to
the semiconductor wafer has a first layer and a second layer; and the method of finishing having the additional steps of: accessing the stored information comprising at least in part the first progress of finishing information, the second progress of finishing information, the tracking code, and the control logic consistent with the current manufacturing step which was used for controlling the at least one process control parameter for finishing for the second layer; and determining a change to at least two process control parameters using the at least in part the first progress of finishing information, the second progress of finishing information, the tracking code, and the control logic consistent with the current manufacturing step which was used for controlling the at least one control parameter for finishing for the second layer. 51. The method of finishing according to
52. The method of finishing according to
53. The method of finishing according to
54. The method of finishing according to
the semiconductor wafer surface comprises a heterogeneous semiconductor wafer surface having different compositions during the finishing cycle time; and having the additional step of: differentially lubricating the different compositions during the finishing cycle time. 55. The method of finishing according to
the finishing element finishing surface has inorganic abrasive particles; and the semiconductor wafer surface comprises a heterogeneous semiconductor wafer surface having different compositions during the finishing cycle time; and having the additional step of: differentially lubricating the different compositions during the finishing cycle time. 56. The method of finishing according to
providing a finishing composition which chemically reacts preferentially with a portion of the semiconductor wafer surface.
57. The method of finishing according to
providing a finishing composition which is free of abrasive particles and which chemically reacts preferentially with a portion of the semiconductor wafer surface; and wherein: the finishing element finishing surface has abrasive particles. 58. The method of finishing according to
59. The method of finishing according to
60. The method of finishing according to
61. The method of finishing according to
using the stored information to determine a process control parameter for a subsequent finishing step; and controlling the process control parameter in a subsequent finishing step.
62. The method of finishing according to
using the stored information to make an appreciable change to a process model having an organic lubricating control parameter; using the stored information to determine a process control parameter for a subsequent finishing step; and controlling the process control parameter in a subsequent finishing step.
63. The method of finishing according to
using the stored information to make an appreciable change to a process model having a plurality of organic lubricating control parameters; using the stored information to determine a process control parameter for a subsequent finishing step; and controlling the process control parameter in a subsequent finishing step.
65. The method of finishing according to
66. The method of finishing according to
semiconductor wafer has a tracking code; and wherein: the processor has access to look-up tables, the tracking code, and a historical performance; and prior to controlling the marginal organic lubricating film having the additional step of: determining a change to the at least one control parameter with the control subsystem using at least in part the tracking code, the in situ finishing information, and the historical performance before controlling the marginal organic lubricating film. 67. The method of finishing according to
68. The method of finishing according to
69. The method of finishing according to
70. The method of finishing according to
71. The method of finishing according to
72. The method of finishing according to
73. The method of finishing according to
74. The method of
providing a finishing composition free of abrasive particles between the semiconductor wafer surface and the finishing element finishing surface.
75. The method of
providing a finishing composition free of abrasive particles between the semiconductor wafer surface and the finishing element finishing surface; and wherein the finishing element finishing surface is free of inorganic abrasive particles.
76. The method of
providing a finishing composition free of abrasive particles between the semiconductor wafer surface and the finishing element finishing surface.
77. The method of
providing a finishing composition free of abrasive particles between the semiconductor wafer surface and the finishing element finishing surface; and wherein the finishing element finishing surface is free of inorganic abrasive particles.
78. The method of finishing according to
79. The method of finishing according to
the semiconductor wafer surface comprises a heterogeneous semiconductor wafer surface having different compositions during the finishing cycle time; and having the additional step of: differentially lubricating the different compositions during the finishing cycle time. 80. The method of finishing according to
the finishing element finishing surface comprises a fixed abrasive finishing element finishing surface; and the semiconductor wafer surface comprises a heterogeneous semiconductor wafer surface having different compositions during the finishing cycle time; and having the additional step of: differentially lubricating the different compositions during the finishing cycle time. 81. The method of finishing according to
providing a finishing composition which chemically reacts preferentially with a portion of the semiconductor wafer surface.
82. The method of finishing according to
providing a finishing composition which is free of abrasive particles and which chemically reacts preferentially with a portion of the semiconductor wafer surface; and wherein: the finishing element finishing surface comprises an abrasive finishing surface. 85. The method of finishing according to
86. The method of
providing a finishing composition free of abrasive particles between the semiconductor wafer surface and the finishing element finishing surface; and wherein the finishing element finishing surface is free of inorganic abrasive particles.
87. The method of finishing according to
88. The method of
providing a finishing composition free of abrasive particles between the semiconductor wafer surface and the finishing element finishing surface.
89. The method of finishing according to
90. The method of finishing according to
using the stored information to determine a process control parameter for a subsequent finishing step; and controlling the process control parameter in a subsequent finishing step.
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This application claims benefit of Provisional Application serial No. 60/107,301 filed on Nov. 6, 1998 entitled "Method of finishing with a fixed abrasive finishing element having finishing aids"; Provisional Application serial No. 60/111,969 filed on Dec. 11, 1998 entitled "Finishing semiconductor wafers with a multi-layer fixed abrasive finishing element having finishing aids", Ser. No. 60/225,897 filed on Mar. 15, 2001 entitled "Finishing semiconductors with a lubricating layer", Ser. No. 60/293263 filed on May 24, 2001 entitled "Finishing element having finishing aids finishing method" and Ser. No. 60/365453 filed on Mar. 19, 2002 with the title "Finishing with self-assembling lubricants". This application claims benefit of Regular application Ser. No. 09/434,723 now U.S. Pat. No. 6,267,644 filed on Jan. 5, 1999 entitled "Fixed abrasive finishing element having finishing aids method", Regular application Ser. No. 09/498,265 now U.S. Pat. No. 6,390,890 filed on Feb. 3, 2000 entitled "Finishing semiconductor wafers with a fixed abrasive finishing element" and Regular application Ser. No. 09/916,428 filed Jul. 26, 2001 now U.S. Pat. No. 6,928,388 and a CIP with the title "Finishing element with finishing aids".
Provisional Applications and Regular Applications above are included herein by reference in their entirety.
Chemical mechanical polishing (CMP) is generally known in the art. For example U.S. Pat. No. 5,177,908 to Tuttle issued in 1993 describes a finishing element for semiconductor wafers, having a face shaped to provide a constant, or nearly constant, surface contact rate to a workpiece such as a semiconductor wafer in order to effect improved planarity of the workpiece. U.S. Pat. No. 5,234,867 to Schultz et. al. issued in 1993 describes an apparatus for planarizing semiconductor wafers which in a preferred form includes a rotatable platen for polishing a surface of the semiconductor wafer and a motor for rotating the platen and a non-circular pad is mounted atop the platen to engage and polish the surface of the semiconductor wafer. Fixed abrasive finishing elements are known for polishing semiconductor layers. An example is WO 98/18159 PCT application by Minnesota Mining and Manufacturing.
An objective of polishing of semiconductor layers is to make the semiconductor layers as nearly perfect as possible. Fixed abrasive finishing pad finishing surfaces can suffer from being overly harsh on a workpiece causing unwanted scratching or other unwanted surface damage thus reducing the perfection of the surface. Further, a fixed abrasive finishing pad finishing surface can suffer from having a higher than necessary friction when finishing a workpiece. This higher than necessary friction can lead to other unwanted surface damage. Further, fixed abrasive finishing pads can have abrasive particles unexpectedly break away from their surface during finishing and these broken away abrasive particles can scratch or damage the workpiece surface. Still further, during finishing a particle can break away from the workpiece surface forming a workpiece abrasive particle which can scratch or damage the workpiece surface. These unwanted effects are particularly important and deleterious to yield when manufacturing electronic wafers which require extremely close tolerances in required planarity and feature sizes.
It is an advantage of this invention to reduce the harshness of fixed abrasive finishing pads on the workpiece surface being finished. It is an advantage of this invention to reduce unwanted scratching or other unwanted surface damage on the workpiece surface during finishing. It is further an advantage of this invention to reduce the friction during finishing to help reduce unwanted surface damage. It is an advantage of this invention to reduce unwanted damage to the workpiece surface when during finishing with a fixed abrasive finishing element an abrasive particle unexpectedly breaks away from their surface. It is an advantage of the invention to reduce unwanted damage to the workpiece surface when an abrasive workpiece particle breaks away workpiece surface during finishing. It is further an advantage of invention to develop new control methods for lubricated finishing including methods to improve a process control model. It is further an advantage of this invention to help improve yield for workpieces having extremely close tolerances such as semiconductor wafers.
These and other advantages of the invention will become readily apparent to those of ordinary skill in the art after reading the following disclosure of the invention.
A preferred embodiment of this invention is directed to a method of finishing a semiconductor wafer having a semiconductor wafer surface comprising a step of providing a finishing element finishing surface comprising a polymer; a step of positioning the semiconductor wafer surface proximate to the finishing surface; a step of providing an organic lubricant proximate to the surface of the semiconductor wafer surface being finished; a step of applying an operative finishing motion in an interface between the semiconductor wafer surface and the finishing element finishing surface; and wherein applying the operative finishing motion forms an organic lubricating film layer of at most 10 molecules thick which self-assembles with and adheres to the semiconductor wafer surface being finished.
A preferred embodiment of this invention is directed to a method of finishing of a semiconductor wafer surface having a first uniform region surface and a second uniform region surface comprising a step of providing a finishing surface comprising at least in part an organic polymer; a step of providing a control subsystem having a plurality of operative sensors, a controller, and a processor having access to look-up tables and historical performance; a step of positioning the semiconductor wafer surface proximate to the finishing surface; a step of providing an organic lubricant between the finishing surface and the first and second uniform region surfaces of the semiconductor wafer surface; a step of applying an operative finishing motion that transfers the organic lubricant from the finishing surface to an interface comprising the finishing surface and the first and second uniform region surfaces forming a self-assembling organic lubricating film on at least the first uniform region surface; a step of sensing progress of finishing information with the plurality of operative sensors; a step of determining a change to a process control parameter using progress of finishing information, the look-up tables, and the historical performance; and a step of changing the at least one process control parameter in a manner that changes the coefficient of friction in at least one of the first and second uniform region surfaces during at least a portion of the finishing cycle time.
A preferred embodiment of this invention is directed to a method of finishing a semiconductor wafer surface having a uniform region surface comprising a step of providing a finishing surface; a step of providing an organic lubricant between the abrasive finishing surface and the conductive region surface; and a step of applying an operative finishing motion between the semiconductor wafer surface and the finishing surface forming a organic lubricating film of at most 10 molecules thick on the conductive region of the semiconductor wafer surface wherein the operative finishing motion forms a friction in the interface between the conductive region on the semiconductor wafer surface and the abrasive finishing surface; and the organic lubricating film interacts with and self-assembles with the uniform region surface to reduce the coefficient of friction.
A preferred embodiment of this invention is directed to a method of finishing a semiconductor wafer having a semiconductor wafer surface and a tracking code comprising a step of providing an finishing element finishing surface; a step of providing an organic lubricant to an interface between the finishing element finishing surface and the semiconductor wafer surface; a step of providing a control subsystem having a processor, a plurality of operative sensors, and a controller and wherein the processor has access to access to the tracking code, look-up tables, and a control logic consistent with the current manufacturing step; and a step of applying an operative finishing motion to the interface between the abrasive finishing element finishing surface and the semiconductor wafer surface forming an organic lubricating film which adheres to at least a portion of the semiconductor wafer surface; a step of sensing a first progress of finishing information with the plurality of operative sensors; a step of determining a change to at least one process control parameter at least in part using the progress of finishing information, the tracking code, look-up tables, and the control logic consistent with the current manufacturing step; a step of changing the at least one process control parameter; a step of sensing a second progress of finishing information with the plurality of operative sensors after changing the at least one process control parameter; a step of storing at least in part the first progress of finishing information, the second progress of finishing information, the tracking code, and the control logic consistent with the current manufacturing step which was used.
A preferred embodiment of this invention is directed to a method of finishing a semiconductor wafer surface having uniform regions, the method comprising a step of providing an finishing element finishing surface; a step of providing an organic lubricant to an interface between the semiconductor wafer surface and the finishing element finishing surface; and a step of applying an operative finishing motion forming a marginal organic lubricating film on at least a portion of the semiconductor wafer surface and wherein the operative finishing motion forms a friction in the interface between the uniform regions of the semiconductor wafer surface and the finishing element finishing surface; a step of self-assembling of a marginal organic lubricating film with the uniform regions of the semiconductor wafer surface during at least a portion of the finishing cycle time; a step of sensing in situ finishing information with at least one operative sensor; and a step of controlling the marginal organic lubricating film by changing at least one control parameter in a manner that changes the coefficient of friction in at least two different uniform regions of the interface between the semiconductor wafer surface and the finishing element finishing surface in response to an in situ control signal during at least a portion of the finishing cycle time.
A preferred embodiment of this invention is directed to a method of finishing of a semiconductor wafer surface having a first uniform region surface and a second uniform region surface comprising a step of providing a finishing element finishing surface; a step of providing an organic lubricant to an operative finishing interface; and a step of applying an operative finishing motion to the interface formed between the finishing element finishing surface and the first and second uniform region surfaces forming a marginal organic lubricating film on at least the first uniform region surface and wherein the operative finishing motion forms a friction in the interface between the semiconductor wafer surface and the finishing element finishing surface and the marginal organic lubricating film self-assembles with and adheres to at least the first uniform region; and a step of controlling the marginal organic lubricating film by changing at least one control parameter in a manner that changes the coefficient of friction in at least the first uniform region in response to an in situ control signal during at least a portion of the finishing cycle time; and a step of inducing differential tribochemical wear to at least a portion of the semiconductor wafer surface.
A preferred embodiment of this invention is directed to a method of finishing a semiconductor wafer having a semiconductor wafer surface and a tracking code comprising a step of providing an finishing element finishing surface; a step of providing a finishing aid to an interface between the finishing element finishing surface and the semiconductor wafer surface and wherein the finishing aid is selected from the group consisting of a lubricating aid and chemically reactive aid; a step of providing a control subsystem having a processor, a plurality of operative sensors, and a controller and wherein the processor has access to access to the tracking code, look-up tables, and a control logic consistent with the current manufacturing step; and a step of applying an operative finishing motion to the interface between the abrasive finishing element finishing surface and the semiconductor wafer surface forming a reaction between the reactive finishing aid and the semiconductor wafer on a portion of the semiconductor wafer surface; a step of sensing a first progress of finishing information with the plurality of operative sensors; a step of determining a change to at least one process control parameter at least in part using the progress of finishing information, the tracking code, look-up tables, and the control logic consistent with the current manufacturing step; a step of changing the at least one process control parameter; a step of sensing a second progress of finishing information with the plurality of operative sensors after changing the at least one process control parameter; a step of storing at least in part the first progress of finishing information, the second progress of finishing information, the tracking code, and the control logic consistent with the current manufacturing step which was used.
Other preferred embodiments of my invention are described herein.
Reference numerals in the drawings
Reference Numeral 4 direction of rotation of the finishing element finishing surface
Reference Numeral 6 direction of rotation of the workpiece being finished
Reference Numeral 8 center of the rotation of the workpiece
Reference Numeral 10 finishing composition feed line for adding finishing chemicals
Reference Numeral 12 reservoir of finishing composition
Reference Numeral 14 alternate finishing composition feed line for adding alternate finishing chemicals
Reference Numeral 16 a reservoir of alternate finishing composition
Reference Numeral 16 rotating carrier for the workpiece
Reference Numeral 18 operative contact element
Reference Numeral 20 workpiece
Reference Numeral 21 workpiece surface facing away from the workpiece surface being finished.
Reference Numeral 22 surface of the workpiece being finished
Reference Numeral 23 raised surface perturbation
Reference Numeral 24 finishing element
Reference Numeral 25 optional fixed abrasive particles proximate the finishing element finishing surface.
Reference Numeral 26 finishing element finishing surface
Reference Numeral 27 optional finishing aid in the form of discrete regions
Reference Numeral 28 finishing element surface facing away from workpiece surface being finished
Reference Numeral 29 finishing element surface layer
Reference Numeral 30 finishing composition
Reference Numeral 31 optional direction of pressure applied to interface
Reference Numeral 32 operative finishing motion
Reference Numeral 33 pressure applied to the operative finishing interface substantially perpendicular to the finishing motion
Reference Numeral 40 platen
Reference Numeral 42 surface of the platen facing the finishing element
Reference Numeral 44 surface of the platen facing away from the finishing element
Reference Numeral 54 base support structure
Reference Numeral 56 surface of the base support structure facing the platen
Reference Numeral 60 carrier housing
Reference Numeral 62 pressure distributive element
Reference Numeral 500 operative sensor
Reference Numeral 510 processor
Reference Numeral 520 controller
Reference Numeral 800 portion of a semiconductor wafer surface having two unwanted raised regions.
Reference Numeral 802 unwanted raised regions on the semiconductor surface being finished.
Reference Numeral 804 lower local regions on the semiconductor surface being finished proximate to the unwanted raised regions.
Reference Numeral 810 finishing surface contacting unwanted raised regions
Reference Numeral 812 finishing element surface local region displaced from but proximate to and lower than the unwanted raised local regions.
Reference Numeral 900 boundary layer lubrication.
Reference Numeral 902 thinner regions of boundary layer lubrication
Reference Numeral 904 thicker regions of boundary layer lubrication
The book Chemical Mechanical Planarization of Microelectric Materials by Steigerwald, J. M. et al published by John Wiley & Sons, ISBN 0471138274 generally describes chemical mechanical finishing and is included herein by reference in its entirety for general background. In chemical mechanical finishing the workpiece is generally separated from the finishing element by a polishing slurry. The workpiece surface being finished is in parallel motion with finishing element finishing surface disposed towards the workpiece surface being finished. The abrasive particles such as found in a polishing slurry interposed between these surfaces finish the workpiece.
Discussion of some of the terms useful to aid in understanding this invention are now presented. Finishing is a term used herein for both planarizing and polishing. Planarizing is the process of making a surface which has raised surface perturbations or cupped lower areas into a planar surface and thus involves reducing or eliminating the raised surface perturbations and cupped lower areas. Planarizing changes the topography of the work piece from non planar to ideally perfectly planar. Polishing is the process of smoothing or polishing the surface of an object and tends to follow the topography of the workpiece surface being polished. A finishing element is a term used herein to describe a pad or element for both polishing and planarizing. A finishing element finishing surface is a term used herein for a finishing element surface used for both polishing and planarizing. A finishing element planarizing surface is a term used herein for a finishing element surface used for planarizing. A finishing element polishing surface is a term used herein for a finishing element surface used for polishing. Workpiece surface being finished is a term used herein for a workpiece surface undergoing either or both polishing and planarizing. A workpiece surface being planarized is a workpiece surface undergoing planarizing. A workpiece surface being polished is a workpiece surface undergoing polishing. The finishing cycle time is the elapsed time in minutes that the workpiece is being finished. A portion of a finishing cycle time is about 5% to 95% of the total finishing cycle time in minutes and a more preferred portion of a finishing cycle time is 10% to 90% of the total finishing cycle time in minutes. The planarizing cycle time is the elapsed time in minutes that the workpiece is being planarized. The polishing cycle time is the elapsed time in minutes that the workpiece is being polishing.
As used herein, an emulsion is a fluid containing a microscopically heterogeneous mixture of two (2) normally immiscible liquid phases, in which one liquid forms minute droplets suspended in the other liquid. As used herein, a surfactant is a surface active substance, i. e., alters (usually reduces) the surface tension of water. Non limiting examples of surfactants include ionic, nonionic, and cationic. As used herein, a lubricant is an agent that reduces friction between moving surfaces. A hydrocarbon oil is a non limiting example. As used herein, soluble means capable of mixing with a liquid (dissolving) to form a homogeneous mixture (solution).
As used herein, a dispersion is a fluid containing a microscopically heterogeneous mixture of solid phase material dispersed in a liquid and in which the solid phase material is in minute particles suspended in the liquid. As used herein, a surfactant is a surface active substance, i. e., alters (usually reduces) the surface tension of water. Non limiting examples of surfactants include ionic, nonionic, and cationic. As used herein, a lubricant is an agent that reduces friction between moving surfaces. As used herein, soluble means capable of mixing with a liquid (dissolving) to form a homogeneous mixture (solution).
As used herein, a die is one unit on a semiconductor wafer generally separated by scribe lines. After the semiconductor wafer fabrication steps are completed, the die are separated into units generally by sawing. The separated units are generally referred to as "chips". Each semiconductor wafer generally has many die which are generally rectangular. The terminology semiconductor wafer and die are generally known to those skilled in the arts. As used herein, within die uniformity refers to the uniformity of within the die. As used herein, local planarity refers to die planarity unless specifically defined otherwise. Within wafer uniformity refers to the uniformity of finishing of the wafer. As used herein, wafer planarity refers to planarity across a wafer. Multiple die planarity is the planarity across a defined number of die. As used herein, global wafer planarity refers to planarity across the entire semiconductor wafer planarity. Planarity is important for the photolithography step generally common to semiconductor wafer processing, particularly where feature sizes are less than 0.25 microns. As used herein, a device is a discrete circuit such as a transistor, resistor, or capacitor. As used herein, pattern density is ratio of the raised (up) area in square millimeters to the to area in square millimeters of region on a specific region such as a die or semiconductor wafer. As used herein, pattern density is ratio of the raised (up) area in square millimeters to the total area in square millimeters of region on a specific region such as a die or semiconductor wafer. As used herein, line pattern density is the ratio of the line width to the pitch. As used herein, pitch is line width plus the oxide space. As an illustrative example, pitch is the copper line width plus the oxide spacing. Oxide pattern density, as used herein, is the volume fraction of the oxide within an infinitesimally thin surface of the die.
As used herein, "appreciable" means "capable of being readily perceived or estimated; considerable".
A fixed abrasive finishing element finishing surface tends to have a higher friction than necessary with the workpiece being finished. The higher friction can lead to higher than necessary energy for finishing. The higher friction can lead to destructive surface forces on the workpiece surface which cause deleterious surface damage to the workpiece. Further the higher the tangential frictional forces can cause mechanical failure in some semiconductor wafer such as those having a plurality of metal layers, even more particularly when low-k dielectric layers are also incorporated in the semiconductor wafer structure. The higher friction can lead to premature wear on the finishing element and the abrasive particles themselves. This premature wear on the finishing element and abrasive particles themselves can unnecessarily increase the cost of finishing a workpiece. Further, this higher than necessary friction can lead to higher than necessary changes in performance of the finishing element finishing surface during the finishing of a plurality of workpieces which makes process control more difficult and/or complex. Applicant currently believes that the higher than desirable defects in the workpiece surface being finished can at least partially due to the fact that the abrasive particles in a previous fixed abrasive finishing elements tend to scratch or gouge the surface because they are not free to move as compared to abrasive particles in a fluid slurry which are free to roll and move during finishing. Further, since the fixed abrasive finishing element has fixed abrasive particles in a constant relative position versus the workpiece surface being finished, applicant believes it is easier for finishing surface of the abrasive particles to become dull or less effective at finishing the workpiece surface being finished when compared to abrasive particles in a slurry. Each of the above situations can lead to less than desirable surface quality on the workpiece surface being finished and earlier than necessary wear on the expensive fixed abrasive finishing element finishing surface. Applicant currently believes that proper choice of a finishing aid, more preferably a lubricating aid, even more preferably a reactive finishing aid, at or proximate the surface of the finishing element finishing surface can reduce or eliminate the high tendency to scratch and/or damage workpiece surface being finished. Applicant currently believes that proper choice and supply of a finishing aid, more preferably a lubricating aid, from the finishing element to the interface of the workpiece surface being finished and the finishing element finishing surface can reduce or eliminate the negative effects of high friction such as chatter. Applicant currently believes that proper choice and supply of a finishing aid to the interface of the workpiece surface being finished and the finishing element finishing surface can extend the useful life of the finishing element finishing surface by reducing erosive and other wear forces. A finishing aid, more preferably a lubricating aid, reduces the wear to the tips of the abrasive particles due to attrition wear and tribochemical wear. Thus the lubricating aid can help to maintain the "cutting ability" of the abrasive particles. Supplying the lubricating aid at the point of use from the finishing element finishing surface can reduce or prevent negative interactions between the finishing composition and any lubricating aid which might be added to the finishing composition (and optional slurry particles therein). Supplying the lubricating aid from the finishing element finishing surface can further reduce the of chatter, micro localized distortions in the finishing element finishing surface, and also increases the uniformity of finishing across the surface of the workpiece surface being finished. Preferably the lubricating aid is dispersed proximate the finishing element finishing surface and more preferably, the lubricating aid is dispersed substantially uniformly proximate the finishing element finishing surface. Supplying an organic lubricating film and/or an organic boundary lubricant to the operative finishing interface (located between finishing element finishing surface and the workpiece surface being finished) further reduces risks of chatter, micro localized distortions in the finishing element finishing surface, and also increases the uniformity of finishing across the surface of the workpiece surface being finished. Forming the lubricating boundary layer differentially can improve local planarity and enhance finishing flexibility as discussed herein. Lubrication reduces abrasive wear to the abrasive particles and to the finishing element finishing surface by reducing friction forces. Differential boundary lubrication can enhance localized finishing rates to improve the semiconductor wafer surface. Lubrication reduces breaking away of the abrasive particles from the surface of the fixed abrasive finishing element by reducing friction forces. Lubrication reduces the friction which can reduce adverse forces particularly on a high speed belt fixed abrasive finishing element which under high friction can cause belt chatter, localized belt stretching, and/or belt distortions, high tendency to scratch and/or damage workpiece surface being finished. Localized and or micro localized distortions to the surface of a fixed abrasive finishing element and chatter can also occur with other finishing motions and/elements and lubrication can reduce or eliminate these.
Supplying of finishing aid from the finishing element finishing surface to the interface of the workpiece surface being finished and the finishing element finishing surface to extend the finishing element finishing surface useful life is preferred. Supplying of finishing aid from the finishing element finishing surface to the interface of the workpiece surface being finished and the finishing element finishing surface to reduce unwanted surface defects in the workpiece surface being finished is preferred. Supplying of finishing aid from the finishing element finishing surface to the interface of the workpiece surface being finished and the finishing element finishing surface to reduce unwanted breaking away of abrasive particles from the fixed abrasive finishing element finishing surface is preferred. Supply of lubricant at the point of use is preferred and supply of lubricant with a substantially uniform way or with a substantially uniform method to the operative finishing interface at the point of use is currently more preferred. An effective amount of finishing aid from the finishing element finishing surface often can help meeting a plurality of these objectives simultaneously. Supply of an organic lubricating film is particularly preferred. Forming a self-assembling lubricating film on at least a portion of the workpiece during the finishing cycle time to reduce the coefficient of friction is preferred. Applying an operative finishing motion forming an organic lubricating film which self-assembles on at least a portion of the workpiece surface during the finishing cycle time to reduce the coefficient of friction is more preferred. Applying an operative finishing motion forming an organic lubricating film which self-assembles on at least a portion of a workpiece surface and wherein the workpiece surface changes during the finishing cycle time is more preferred. Applying an operative finishing motion forming an organic lubricating film which self-assembles on a dynamically changing workpiece uniform region surface during the finishing cycle time is also more preferred. Supply of a thin lubricating boundary layer is particularly preferred. An effective amount of boundary lubricant often can help meeting a plurality of these advantages simultaneously. A self-assembling lubricating film can be used enhance control of a dynamically changing workpiece surface and enhance manufacturing.
The new problem recognition and unique solution are new and considered part of this current invention.
Optional Abrasive Finishing Element
A finishing element having fixed abrasives for finishing high precision workpieces is known. As used herein, a fixed abrasive finishing element is an integral abrasive finishing element. The integral abrasive finishing element having abrasive particles connected to at least the surface of the finishing element finishing surface layer is preferred. The integral abrasive finishing element surface layer having abrasive particles connected to at least the surface of the finishing element and which is substantially free of unconnected abrasive particles except for those formed during the actual planarizing and/or polishing process itself is more preferred. A three dimensional fixed abrasive finishing element surface layer as used herein is a fixed abrasive finishing element surface layer having multiple abrasive particles dispersed throughout at least a portion of its thickness, such that if some of the surface is removed additional abrasive particles are exposed on the newly exposed surface. A three dimensional fixed abrasive finishing element surface layer is particularly preferred. A three dimensional fixed abrasive finishing element surface layer having multiple abrasive particles substantially uniformly dispersed throughout at least a portion of its thickness such that if some of the surface is removed another region of substantially uniformly dispersed abrasive particles are exposed on the newly exposed surface is preferred. A three dimensional fixed abrasive finishing element surface layer having multiple abrasive particles uniformly dispersed throughout at least as portion of its thickness such that if some of the surface is removed another region of uniformly dispersed abrasive particles are exposed on the newly exposed surface is more preferred. A fixed abrasive finishing element surface layer which applies a substantially uniform distribution of abrasive particles over the workpiece surface being finished is preferred and a fixed abrasive finishing element surface layer which applies a uniform distribution of abrasive particles over the workpiece surface being finished is more preferred.
An abrasive finishing element surface layer and a finishing element subsurface layer free of finishing aids comprising a synthetic polymeric is preferred. A synthetic polymeric layer comprising at least one material selected from the group consisting of an organic synthetic polymer, an inorganic polymer, and combinations thereof is preferred. A preferred example of organic synthetic polymer is an thermoplastic polymer. Another preferred example of an organic synthetic polymer is a thermoset polymer. An organic synthetic polymeric body comprising organic synthetic polymers including materials selected from the group consisting of polyurethanes, polyolefins, polyesters, polyamides, polystyrenes, polycarbonates, polyvinyl chlorides, polyimides, epoxies, chloroprene rubbers, ethylene propylene elastomers, butyl polymers, polybutadienes, polyisoprenes, EPDM elastomers, and styrene butadiene elastomers is preferred. Preferred stiff finishing surfaces can comprise polyphenylene sulfide, polysulfone, and polyphenylene oxide polymers. Phenolic polymers can also be used. Polyolefin polymers are particularly preferred for their generally low cost. A preferred polyolefin polymer is polyethylene. Another preferred polyolefin polymer is a propylene polymer. Another preferred polyolefin polymer is a ethylene propylene copolymer. Copolymer organic synthetic polymers are also preferred. Polyurethanes are preferred for the inherent flexibility in formulations. A finishing element comprising a foamed organic synthetic polymer is particularly preferred because of their flexibility and ability to transport the finishing composition. A finishing element comprising a foamed polyurethane polymer is particularly preferred. Foaming agents and processes to foam organic synthetic polymers are generally known in the art. A finishing element comprising a compressible porous material is preferred and comprising a organic synthetic polymer of a compressible porous material is more preferred.
A finishing element finishing surface layer including a substantially uniform mixture of a plurality of organic synthetic polymers can be particularly tough, wear resistant, and useful. A finishing element having a body element comprised of a mixture of a plurality of organic synthetic polymers can be particularly tough, wear resistant, and useful. An organic synthetic polymeric finishing element finishing surface comprising a plurality of organic synthetic polymers and wherein the major component is selected from materials selected from the group consisting of polyurethanes, polyolefins, polyesters, polyamides, polystyrenes, polycarbonates, polyvinyl chlorides, polyimides, epoxies, chloroprene rubbers, ethylene propylene elastomers, butyl polymers, polybutadienes, polyisoprenes, EPDM elastomers, and styrene butadiene elastomers is preferred. Preferred stiff finishing surfaces can comprise polyphenylene sulfide, polysulfone, and polyphenylene oxide resins. Phenolic resins can also be used. The minor component is preferably also an organic synthetic polymer and is preferably a modifying and/or toughening agent. A preferred example of an organic synthetic polymer modifier is a material which reduces the hardness or flex modulus of the finishing element body such an polymeric elastomer. A compatibilizing agent can also be used to improve the physical properties of the polymeric mixture. Compatibilizing agents are often also synthetic polymers and have polar and/or reactive functional groups such as carboxylic acid, maleic anhydride, and epoxy groups. Organic synthetic polymers of the above descriptions are generally available commercially. Illustrative nonlimiting examples of commercial suppliers of organic synthetic polymers include Exxon Co., Dow Chemical, Sumitomo Chemical, and BASF.
An abrasive finishing element comprising a synthetic polymer composition having a plurality of layers is preferred. A fixed abrasive finishing element comprising at least one layer of a soft synthetic polymer is preferred. A fixed abrasive finishing element comprising at least one layer of a elastomeric synthetic polymer is preferred. A fixed abrasive finishing element comprising at least one layer of a thermoset elastomeric synthetic polymer is preferred.
Further illustrative nonlimiting examples of preferred finishing elements for use in the invention are also discussed. A finishing element having at least a layer of an elastomeric material having a Shore A hardness of at least 30 A is preferred. ASTM D 676 is used to measure hardness. A porous finishing element is preferred to more effectively transfer the polishing slurry to the surface of the workpiece being finished. A finishing element comprising a synthetic resin material is preferred. A finishing element comprising a thermoset resin material is more preferred. A finishing element having layers of different compositions is preferred to improve the operative finishing motion on the workpiece surface being finished. As an example, a finishing element having two layers, one a hard layer and one a soft layer, can better transfer the energy of operative finishing motion to the workpiece surface being finished than a similar thickness finishing element of only a very soft layer. A thermoset synthetic resin is less prone to elastic flow and thus is more stable in this application. A finishing element which is thin is preferred because it generally transfers the operative finishing motion to the workpiece surface being finished more efficiently. A finishing element having a thickness from 0.5 to 0.002 cm is preferred and a thickness from 0.3 to 0.005 cm is more preferred and a finishing element having a thickness from 0.2 to 0.01 cm is even more preferred. Current synthetic resin materials can be made quite thin now. The minimum thickness will be determined by the finishing element's integrity and longevity during polishing which will depend on such parameters as tensile and tear strength. A finishing element having sufficient strength and tear strength for chemical mechanical finishing is preferred.
An abrasive finishing element having a flex modulus in particular ranges is also preferred. An abrasive finishing element having a high flex modulus is generally more efficient for planarizing. An abrasive finishing element having a low flex modulus is generally more efficient for polishing. Further a continuous belt fixed abrasive finishing element can have a different optimum flex modulus than a fixed abrasive finishing element disk. One also needs to consider the workpiece surface to be finished in selecting the flex modulus. A fixed abrasive finishing element comprising a synthetic resin having flex modulus of at most 1,000,000 psi is preferred and having flex modulus of at most 800,000 psi is more preferred and 500,000 psi is more preferred. Pounds per square in is psi. Flex modulus is preferably measured with ASTM 790 B at 73 degrees Fahrenheit. Fixed abrasive finishing elements comprising a synthetic resin having a very low flex modulus are also generally known to those skilled in the art such as elastomeric polynrethanes which can also be used. A finishing element having a flex modulus of greater than 1,000,000 psi can be preferred for some particular planarizing applications.
For some embodiments, polishing pad designs and equipment such as in U.S. Pat. No. 5,702,290 to Leach, a polishing pad having a high flexural modulus can be effective and preferred. A finishing element having a continuous phase of material imparting resistance to local flexing is preferred. A preferred finishing element has a finishing surface comprising a multiphase polymeric finishing surface. A more preferred finishing element has a finishing surface comprising a multiphase polymeric finishing surface having at least two synthetic polymers (e.g. separate polymeric components). An even more preferred finishing element has a finishing comprising a multiphase polymeric finishing surface having at least three synthetic polymers (e.g. separate polymeric components). A preferred continuous phase of material is a synthetic polymer, more preferably an organic synthetic polymer. An organic synthetic polymer having a flexural modulus of at least 50,000 psi is preferred and having a flexural modulus of at least 100,000 psi is more preferred and having a flexural modulus of at least 200,000 psi is even more preferred for the continuous phase of synthetic polymer in the finishing element. An organic synthetic polymer having a flexural modulus of at most 5,000,000 psi is preferred and having a flexural modulus of at most 3,000,000 psi is more preferred and having a flexural modulus of at most 2,000,000 psi is even more preferred for the continuous phase of synthetic polymer in the finishing element. An organic synthetic polymer having a flexural modulus of from 5,000,000 to 50,000 psi is preferred and having a flexural modulus of from 3,000,000 to 100,000 psi is more preferred and having a flexural modulus of at from 2,000,000 to 200,000 psi is even more preferred for the continuous phase of synthetic polymer in the finishing element. For some less demanding applications (such as die with a lower pattern density), a flexural modulus of at least 20,000 psi is preferred. These ranges of flexural modulus for the synthetic polymers provide useful performance for finishing a semiconductor wafer and can improve local planarity in the semiconductor. Flexural modulus is preferably measured with ASTM 790 B at 73 degrees Fahrenheit. Pounds per square inch is psi.
An abrasive finishing element having Young's modulus in particular ranges is also preferred. An abrasive finishing element having a high Young's modulus is generally more efficient for planarizing. An abrasive finishing element having a low Young's modulus is generally more efficient for polishing. Further a continuous belt fixed abrasive finishing element can have a different optimum Young's modulus than a fixed abrasive finishing element disk. One also needs to consider the workpiece surface to be finished in selecting the Young's modulus. For a flexible abrasive finishing element having a Young's modulus from 100 to 700,000 psi (pounds per square in inch) is preferred and having a Young's modulus from 300 to 200,000 psi (pounds per square in inch) is more preferred and having a Young's modulus from 300 to 150,000 psi (pounds per square in inch) is even more preferred. Particularly stiff abrasive finishing elements can have a preferred Young's modulus of at least 700,000 psi. For particularly flexible abrasive finishing elements, a Young's modulus of less than 100,000 psi are preferred and less than 50,000 psi is more preferred.
An abrasive finishing element having abrasive asperities on the finishing element finishing surface is preferred. An abrasive finishing element having abrasive asperities having a height from 0.9 to 0.005 micrometers is preferred and an abrasive finishing element having abrasive asperities having a height from 0.3 to 0.005 micrometers is more preferred and an abrasive finishing element having abrasive asperities having a height from 0.1 to 0.01 micrometers is even more preferred and an abrasive finishing element having abrasive asperities having a height from 0.05 to 0.005 micrometers is more particularly preferred. The asperities are preferably firmly attached to the finishing element finishing surface and asperities which are an integral part of the finishing element finishing surface are more preferred. Polymeric abrasive asperities can be preferred for some finishing operations. Inorganic abrasive asperities can be preferred also for some finishing operations. Polymeric abrasive asperities, such as abrasive polymeric particles and/or abrasive polymeric material, are generally preferred for finishing softer workpieces and inorganic abrasive asperities are generally preferred for finishing harder workpiece surfaces. An abrasive finishing element having small asperities can finish a workpiece surface to fine tolerances.
Illustrative nonlimiting abrasive particles comprising silica, silicon nitride, alumina, and ceria are preferred. Fumed silica is particularly preferred. A metal oxide is a type of preferred abrasive particle. A particularly preferred particulate abrasive is an abrasive selected from the group consisting of iron (III) oxide, iron (II) oxide, magnesium oxide, barium carbonate, calcium carbonate, manganese dioxide, silicon dioxide, cerium dioxide, cerium oxide, chromium (III) trioxide, and aluminum trioxide. Abrasive particles having an average diameter of less than 0.5 micrometers are preferred and less than 0.3 micrometer are more preferred and less than 0.1 micrometer are even more preferred and less than 0.05 micrometers are even more particularly preferred. Abrasive particles having an average diameter of from 0.5 to 0.01 micrometer are preferred and between 0.3 to 0.01 micrometer are more preferred and between 0.1 to 0.01 micrometer are even more preferred.
Abrasive particles having a different composition from the finishing element body are preferred. An abrasive particle having a Knoop hardness of less than diamond is particularly preferred to reduce microscratches on workpiece surface being finished and a Knoop hardness of less than 50 GPa is more particularly preferred and a Knoop hardness of less than 40 GPa is even more particularly preferred and a Knoop hardness of less than 35 GPa is especially particularly preferred. An abrasive particle having a Knoop hardness of at least 1.5 GPa is preferred and having a Knoop hardness of at least 2 is preferred. An abrasive particle having a Knoop hardness of from 1.5 to 50 GPa is preferred and having a Knoop hardness of from 2 to 40 GPa is preferred and having a Knoop hardness of from 2 to 30 GPa is even more preferred. A fixed abrasive finishing element having a plurality of abrasive particles having at least two different Knoop hardnesses can be preferred.
A reinforcing layer or member can also be included with or attached to finishing element finishing body. A finishing element having a finishing body connected to a reinforcing layer is preferred and a finishing element having a finishing body integral with a reinforcing layer is more preferred. Preferred nonlimiting examples of reinforcing layers or members are fabrics, woven fabrics, film layers, and long fiber reinforcement members. A continuous belt can have substantially continuous fibers therein. Aramid fibers are particularly preferred for their low stretch and excellent strength. The reinforcing layers can attached with illustrative generally known adhesives and various generally known thermal processes such as extrusion coating or bonding.
The fixed abrasive firmly attached to the finishing element finishing surface is preferred. The abrasive can be firmly attached to the finishing element finishing surface with known adhesives and/or mixed into a surface layer of a polymeric layer, preferably an organic polymeric layer. Particular abrasive surface topographies can be preferred for specific applications. Fixed abrasive finishing elements are generally known to those skilled in the art. Some nonlimiting examples include U.S. Pat. No. 4,966,245 to Callinan, U.S. Pat. No. 5,823,855 to Robinson, U.S. Pat. No. 5,692,950 to Rutherford, WO 98/06541 to Rutherford and WO 98/181159 to Hudson are included herein for general guidance and modification of fixed abrasive finishing elements by those skilled in the art.
Finishing Aid
Supplying an effective amount of finishing aid from the finishing element finishing surface layer, more preferably a lubricating aid, which reduces the coefficient of friction between the finishing element finishing surface and the workpiece surface being finished is preferred. Supplying an effective amount of finishing aid from the finishing element finishing surface layer, more preferably a lubricating aid, which reduces the unwanted surface damage to the surface of the workpiece being finished during finishing is preferred. Supplying an effective amount of finishing aid from the finishing element finishing surface layer, more preferably a lubricating aid, which differentially lubricates different regions of the work piece and reduces the unwanted surface damage to at least a portion of the surface of the workpiece being finished during finishing is preferred.
The finishing aid, more preferably a lubricating aid, can help reduce the formation of surface defects for high precision part finishing. Fluid based finishing aid, more preferably a lubricating aid, can help reduction of brittle fracture at the workpiece surface being finished. A method of finishing which adds an effective amount of fluid based finishing aid, more preferably a lubricating aid, to the interface between the finishing element finishing surface and workpiece surface being finished is preferred. A preferred effective amount of fluid based finishing aid, more preferably a lubricating aid, reduces the occurrence of unwanted surface defects. A preferred effective amount of fluid based finishing aid, more preferably a lubricating aid, can reduce the coefficient of friction between the work piece surface being finished and the finishing element finishing surface.
A lubricating aid which is water soluble is preferred. A lubricating aid which has a different solubility in water at different temperatures is more preferred. A degradable finishing aid, more preferably a lubricating aid, is also preferred and a biodegradable finishing aid, more preferably a lubricating aid, is even more preferred. An environmentally friendly finishing aid, more preferably a lubricating aid, is particularly preferred. A water based lubricant formed with water which has low sodium content is also preferred because sodium can have a adverse performance effect on the preferred semiconductor parts being made. A lubricant free of sodium is a preferred lubricant. As used herein a lubricant fluid free of sodium means that the sodium content is below the threshold value of sodium which will adversely impact the performance of a semiconductor wafer or semiconductor parts made therefrom. A finishing aid, more preferably a lubricating aid, free of sodium is preferred. As used herein a finishing aid free of sodium means that the sodium content is below the threshold value of sodium which will adversely impact the performance of a semiconductor wafer or semiconductor parts made therewith.
Certain particularly important workpieces in the semiconductor industry have regions of high conductivity and regions of low conductivity. The higher conductivity regions are often comprised of metallic materials such as tungsten, copper, aluminum, and the like. An illustrative example of a common lower conductivity region is silicon and silicon oxide. A fluid based lubrication which differentially lubricates the two regions is preferred and a fluid based lubricant which substantially differentially lubricates two regions is more preferred. An example of a differential lubrication is if the coefficient of friction is changed by different amounts in one region versus the other region during finishing. An example of differential lubrication is where the boundary lubricant reacts differently with different chemical compositions to create regions having different local regions of tangential friction force and different coefficients of friction. Another example is where the semiconductor surface being finished topography (for instance unwanted raised regions) interact with in the operative finishing interface to create local regions having different tangential friction forces and different coefficients of friction (see for example
Changing the lubrication at least once during the finishing cycle time to change the coefficient of friction between the finishing element finishing surface and the workpiece surface being finished is preferred. Changing the lubrication a plurality of times during the finishing cycle time to change the coefficient of friction between the finishing element finishing surface and the workpiece surface being finished a plurality of times during the finishing cycle time is more preferred. Changing the amount of lubricant at the operative finishing interface is a preferred method to change the lubrication. Changing the composition of the lubricant at the operative finishing interface is a preferred method to change the lubrication. Changing the number of lubricants in the operative finishing interface is a preferred method to change the lubrication. Changing the number of organic lubricating boundary layers in the operative finishing interface is a preferred method to change the lubrication. Changing the composition of organic lubricating boundary layer(s) at the operative finishing interface is a preferred method to change the lubrication. Changing the number of organic lubricating films in the operative finishing interface is a preferred method to change the lubrication. Changing the composition of organic lubricating film(s) in the operative finishing interface is a preferred method to change the lubrication. Changing the form of the organic lubricating boundary layer(s) is a preferred method to change the lubrication. Changing the form of the organic lubricating film(s) is a preferred method to change the lubrication. Supplying an effective amount of lubricant which reduces the unwanted surface damage to the surface of the workpiece being finished during finishing is preferred. Changing the lubrication during the finishing cycle time can improve finishing control and improve finishing performance, particularly where using in situ control as discussed elsewhere herein. Changing lubrication in situ with a control subsystem is particularly preferred. Changing the coefficient of friction in a uniform region of the workpiece is preferred and changing the coefficient of friction in a plurality of uniform regions of the workpiece is more preferred.
A plurality of operative sensors, preferably friction sensors, can aid in an important way in detecting and controlling differential lubrication in the workpieces having heterogeneous surface compositions needing finishing. Differential lubrication with a plurality of lubricants can be preferred because it can improve lubrication and coefficient of friction control. Differential lubrication with a plurality of organic lubricating films can be more preferred because it can further improve lubrication and coefficient of friction control. Differential lubrication with a plurality of organic lubricating boundary layers can be even more preferred because it can further improve lubrication and coefficient of friction control.
An organic lubricating film which interacts with the semiconductor wafer surface is preferred. An organic lubricating film which adheres to the semiconductor wafer surface is preferred. An organic lubricating film which interacts with and adheres to the semiconductor wafer surface is more preferred. An organic lubricating film which interacts with the uniform region of the semiconductor wafer surface is preferred. An organic lubricating film which adheres to the uniform region of the semiconductor wafer surface is preferred. An organic lubricating film which interacts with and adheres to the uniform region of the semiconductor wafer surface is more preferred. A uniform functional region is a preferred uniform region. A conductive region is a preferred uniform functional region. A nonconductive region is a preferred uniform functional region. By having the organic lubricating film interact with and adhere to a uniform region of the semiconductor wafer surface, localized finishing control can be improved and unwanted surface defects can generally be reduced using the teaching and guidance herein. By having the organic lubricating film self-assemble with a uniform region of the semiconductor wafer surface, localized finishing control can be improved, particularly wherein the semiconductor wafer surface is changing in real time during at least a portion of the finishing cycle time, and unwanted surface defects can generally be reduced using the teaching and guidance herein.
An organic lubricating boundary layer which interacts with the semiconductor wafer surface is preferred. An organic lubricating boundary layer which adheres to the semiconductor wafer surface is preferred. An organic lubricating boundary layer which interacts with and adheres to the semiconductor wafer surface is more preferred. An organic lubricating boundary layer which interacts with the uniform region of the semiconductor wafer surface is preferred. An organic lubricating boundary layer which adheres to the uniform region of the semiconductor wafer surface is preferred. An organic lubricating boundary layer which interacts with and adheres to the uniform region of the semiconductor wafer surface is more preferred. A uniform functional region is a preferred uniform region. A conductive region is a preferred uniform functional region. A lower conductive region and a higher conductive region are preferred uniform functional regions. A nonconductive region is a preferred uniform functional region. By having the organic boundary lubricating layer interact with and adhere to a uniform region of the semiconductor wafer surface, localized finishing control can be improved and unwanted surface defects can generally be reduced using the teaching and guidance herein.
A lubricating aid comprising a reactive lubricant is preferred. A lubricating aid comprising a boundary lubricant is also preferred. A reactive lubricant is a lubricant which chemically reacts with the workpiece surface being finished. A boundary layer lubricant is a preferred example of a lubricant which can form a lubricating film on the surface of the workpiece surface. An organic lubricating film is a preferred lubricating film. An organic lubricating film which adheres to the workpiece surface being finished is preferred and an organic lubricating film which interacts with and adheres to the workpiece surface being finished is more preferred. An organic lubricating film which self-assembles with the workpiece surface being finished is preferred and an organic lubricating film which self-assembles with and adheres to the workpiece surface being finished is more preferred. An organic lubricating boundary layer is preferred example of an organic lubricating film. As used herein a boundary lubricant is a thin layer on one or more surfaces which prevents or at least limits, the formation of strong adhesive forces between the workpiece being finished and the finishing element finishing surface and therefore limiting potentially damaging friction junctions between the workpiece surface being finished and the finishing element finishing surface. A boundary layer film has a comparatively low shear strength in tangential loading which reduces the tangential force of friction between the workpiece being finished and the finishing element finishing surface which can reduce surface damage to the workpiece being finished. In other words, boundary lubrication is a lubrication in which friction between two surfaces in relative motion, such as the workpiece surface being finished and the finishing element finishing surface, is determined by the properties of the surfaces, and by the properties of the lubricant other than the viscosity. Organic lubrication layers wherein the friction between two surfaces is dependent on lubricant properties other than viscosity is preferred. Different regional boundary layers on a semiconductor wafer surface being finished can be preferred for some finishing--particularly planarizing. A boundary film generally forms a thin film, perhaps even several molecules thick, and the boundary film formation depends on the physical and chemical interactions with the surface. An organic lubricating film is preferred. A boundary lubricant which forms of thin film can be more preferred.
An organic lubricating film having a thickness from 1 to 10 molecules thick is preferred and an organic lubricating film having a thickness from 1 to 6 molecules thick is more preferred and an organic lubricating film having a thickness from 1 to 4 molecules thick is even more preferred. An organic lubricating film having a thickness from 1 to 10 molecules thick on at least a portion of the workpiece surface being finished is particularly preferred and an organic lubricating film having a thickness from 1 to 6 molecules thick on at least a portion of the workpiece surface being finished is more particularly preferred and an organic lubricating film having a thickness from 1 to 4 molecules thick on at least a portion of the workpiece surface being finished is even more particularly preferred. An organic lubricating film having a thickness of at most 10 molecules thick on at least a portion of the workpiece surface being finished is particularly preferred and an organic lubricating film having a thickness of at most 6 molecules thick on at least a portion of the workpiece surface being finished is more particularly preferred and an organic lubricating film having a thickness of at most 4 molecules thick on at least a portion of the workpiece surface being finished is even more particularly preferred. Thin organic lubricating films can help reduce unwanted surface damage and aid in heterogeneous lubrication.
An organic lubricating boundary layer is a preferred organic lubricating film and is also preferably thin. A boundary lubricant forming a film having a thickness from 1 to 10 molecules thick is preferred and a boundary lubricant forming a film having a thickness from 1 to 6 molecules thick is more preferred and a boundary lubricant forming a film having a thickness from 1 to 4 molecules thick is even more preferred. A boundary lubricant forming a film having a thickness from 1 to 10 molecules thick on at least a portion of the workpiece surface being finished is particularly preferred and a boundary lubricant forming a film having a thickness from 1 to 6 molecules thick on at least a portion of the workpiece surface being finished is more particularly preferred and a boundary lubricant forming a film having a thickness from 1 to 4 molecules thick on at least a portion of the workpiece surface being finished is even more particularly preferred. A boundary lubricant forming a film having a thickness of at most 10 molecules thick on at least a portion of the workpiece surface being finished is particularly preferred and a boundary lubricant forming a film having a thickness of at most 6 molecules thick on at least a portion of the workpiece surface being finished is more particularly preferred and a boundary lubricant forming a film having a thickness of at most 4 molecules thick on at least a portion of the workpiece surface being finished is even more particularly preferred. An operative motion which continues in a substantially uniform direction can improve boundary layer formation and lubrication. A discontinuous operative motion can be used to change the lubricating boundary layer. Boundary lubricants and lubricating films, because of the small amount of required lubricant, are particularly effective finishing aids for inclusion in fixed abrasive finishing elements. The molecular thickness of lubricating boundary layers can be measured with generally known frictional force measures and/or energy change sensors discussed herein. Changing the pressure in the operative finishing interface and/or in the secondary friction sensor interface can be used to determine molecular thickness. Controls can also be used by using various generally known analytical techniques such as spectroscopy and these results used to calibrate target energy change sensors and frictional force measures. Thermal analysis can also be used to measure the quantity of organic boundary layer on a surface and then the thickness calculated. Thermal analysis can be used to determine the efficacy of a particular lubricating boundary layer including solid boundary lubricant zone, boundary liquid lubricant zone, and boundary lubricant desorbed zone and the transition temperatures therebetween. Thermal analysis can also be used for lubricating films.
Heterogeneous lubricating boundary layers can improve finishing and planarizing of some semiconductor wafers where a differential finishing rate is desired in different regions. A semiconductor wafer surface having at least one unwanted raised region wherein the lubricating boundary layer thickness is at most one half the molecular layer thickness of the lubricating boundary layer thickness proximate to the unwanted raised region is preferred. A semiconductor wafer surface having at least one unwanted raised region wherein the boundary lubrication thickness is at most one third the molecular layer thickness of the lubricating boundary layer thickness proximate to the unwanted raised region is more preferred. A semiconductor wafer surface having at least one unwanted raised region wherein the lubricating boundary layer thickness is at most one quarter the molecular layer thickness of the lubricating boundary layer thickness proximate to the unwanted raised region is more preferred. Applications of this technology are further discussed herein elsewhere.
Controlling the thickness of the lubricating boundary layer by changing at least one control parameter in a manner that changes the tangential force of friction in at least one region of the semiconductor wafer surface in response to an in situ control signal is preferred. Controlling the thickness of the lubricating boundary layer by changing at least one control parameter in a manner that changes the tangential force of friction in at least two different regions of the semiconductor wafer surface in response to an in situ control signal is more preferred. Preferably the unwanted raised regions are related to a repeating pattern in the semiconductor wafer die. A plurality of die each having the same repeating pattern on the semiconductor wafer surface being finished is preferred. These repeating patterns are generally created during semiconductor wafer manufacture and can be related to pattern densities. This is because small changes in lubricating boundary layers can change finishing rate, finishing rate selectivity, and finished surface quality.
A reactive organic lubricant is preferred. A reactive organic lubricating film is more preferred. A reactive boundary lubricant is a preferred lubricant. A lubricating boundary layer (or an organic lubricating film) comprising physical adsorption (physisorption) of the lubricant molecules to the semiconductor surface being finished is a preferred lubricating boundary layer (or an organic lubricating film). Van der Waals surface forces are a preferred example of physical adsorption. Dipole-dipole interaction between the boundary lubricant (or an organic lubricating film) and the semiconductor wafer surface being finished is a preferred example of physical adsorption. A reversible dipole-dipole interaction between the boundary lubricant (or an organic lubricating film) and the semiconductor wafer surface is an example of a more preferred physical adsorption lubricating boundary layer (or an organic lubricating film). An organic alcohol is an illustrative preferred example. A polar organic molecule containing the hetereoatom oxygen is preferred. An organic boundary lubricating layer which is a solid film generally has a greater ability to separate the finishing element finishing surface from the semiconductor wafer surface being finished. A heat of adsorption of from 2,000 to 10,000 cal/mole is preferred for physisorption. A physisorption organic boundary lubricating layer is a preferred reversible lubricating layer.
A lubricating boundary layer (or an organic lubricating film) comprising chemisorption of lubricant molecules to the semiconductor wafer being finished is a preferred lubricating boundary layer. In chemisorption, chemical bonds hold the boundary lubricants (or an organic lubricating film) to the semiconductor wafer surface being finished. A self-assembling lubricant, more preferably a self-assembling boundary lubricant (or an organic lubricating film) is preferred. A self-assembling lubricant which interacts with and adheres with at least a portion of the semiconductor wafer surface is also preferred. A self-assembling lubricating film (preferably an organic lubricating film) which interacts with and adheres with at least a portion of the semiconductor wafer surface is also preferred. A self-assembling lubricating film (preferably an organic lubricating film) which interacts with and adheres with at least a portion of the semiconductor wafer surface which is changing during real time finishing is more preferred. As an illustrative example, a reaction of stearic acid forms a "metal soap" thin film on a metal surface. An organic carboxylic acid is a preferred example. Further, the "metal soap" can have a higher melting temperature and thus form regional areas of an organic boundary layer having higher temperature lubricating capacity as discussed further herein below. A heat of absorption of between 10,000 to 100,000 cal/mole is preferred for chemisorption.
A solid film organic boundary lubricating layer generally has a greater ability to separate the finishing element finishing surface from the semiconductor wafer surface being finished. A solid film organic boundary lubricating layer can thus help reduce finishing rates as measured in angstroms per minute (compared to a liquid film). A liquid film organic boundary lubricating layer generally has a lower ability to separate the finishing element finishing surface from the semiconductor wafer surface being finished can thus help increase finishing rates as measured in angstroms per minute (compared to a solid film). The same boundary lubricant can form either solid film organic boundary lubricating layer or a liquid film organic boundary lubricating layer depending on the operative finishing interface process conditions. A reversible organic boundary lubricating layer (which can change from solid to liquid to solid depending on processing conditions such as temperature) is preferred. Finishing a heterogeneous semiconductor wafer surface having at least one unwanted raised region wherein the lubricating boundary layer comprises a liquid film on the unwanted raised region and the lubricating boundary layer comprises a solid film in the region below and proximate to the unwanted raised region is preferred. Finishing a heterogeneous semiconductor wafer surface having at least one unwanted raised region wherein the lubricating boundary layer comprises a higher temperature liquid film on the unwanted raised region and the lubricating boundary layer comprises a lower temperature solid film in the region below and proximate to the unwanted raised region is preferred. Applying an operative finishing motion to the operative finishing interface forming a heterogeneous temperature profile on the semiconductor wafer surface being finishing and wherein the temperature is higher on a plurality of unwanted raised regions of the heterogeneous semiconductor wafer surface and the temperature is lower proximate to and below the plurality of unwanted raised regions of the heterogeneous semiconductor wafer surface and further the plurality of unwanted raised regions have a liquid lubricating films on them and the regions proximate to and below the plurality of unwanted raised regions solid lubricating films on them. See for instance Reference Numerals 802 (unwanted raised region) and 804 (region proximate to and below the unwanted raised region) for further helpful guidance. An example is octadecyl alcohol forms a solid lubricant film on copper at about 20 to 55 degrees centigrade and a liquid film on copper at about 65 to 110 degrees centigrade. An organic boundary lubricating layer that is capable of changing from a solid film to a liquid film in the operative finishing interface temperature range during a finishing cycle time is preferred. An organic boundary lubricating layer that is capable of changing from a solid film to a different physical form in the operative finishing interface temperature range during a finishing cycle time is preferred. An organic boundary lubricating layer that is capable of changing from a liquid film to a different physical form in the operative finishing interface temperature range during a finishing cycle time is preferred. An organic boundary lubricating layer that is capable of changing from a solid film to a liquid film in the temperature range from 20 to 100 degrees centigrade is more preferred. By increasing the finishing rate in the unwanted raised region and lowering the finishing rate in the region proximate to and below the unwanted raised region, planarization can be improved. Changing the lubricating boundary layer film physical form by changing at least one lubrication control parameter in situ based on feed back information from a lubrication control subsystem having an energy change sensor is preferred. Controlling the lubricating boundary layer film physical form by changing at least one lubrication control parameter in situ based on feed back information from a lubrication control subsystem having an energy change sensor is more preferred. Increasing temperature on the unwanted raised region on the semiconductor wafer surface compared to the temperature on the region below the unwanted raised region forming the lubricating boundary layer liquid film on the unwanted raised region and the lubricating boundary layer solid film on at least a portion of the semiconductor wafer surface below the raised region is preferred. Increasing temperature with frictional heat on the unwanted raised region on the semiconductor wafer surface compared to the temperature on the region below the unwanted raised region forming the lubricating boundary layer liquid film on the unwanted raised region and the lubricating boundary layer solid film on at least a portion of the semiconductor wafer surface below the raised region is more preferred. Using and controlling the lubricating boundary layer physical form can help customize finishing for the particular semiconductor wafers needing finishing. The operative motion interacts with the lubricating boundary layer in a new and useful way to finish a workpiece surface, preferably a semiconductor wafer surface.
A boundary lubricant which forms a thin lubricant film on the metal conductor portion of a workpiece surface being finished is particularly preferred. A nonlimiting preferred group of example boundary lubricants include at least one lubricant selected from the group consisting of fats, fatty acids, esters, and soaps. A preferred group of boundary lubricants comprise organic boundary lubricants. Another preferred group of boundary lubricants comprise organic synthetic lubricants. A phosphorous containing compound can be an effective preferred lubricant. A chlorine containing compound can be an effective preferred lubricant. A sulfur containing compound can be an effective preferred lubricant. A nitrogen containing compound can be an effective preferred lubricant. A phosphorous containing compound can be an effective preferred boundary lubricant. A phosphate ester is an example of a preferred phosphorous containing compound which can be an effective boundary lubricant. A chlorine containing compound can be an effective preferred boundary lubricant. A sulfur containing compound can be an effective preferred boundary lubricant. A nitrogen containing compound can be an effective preferred boundary lubricant. A compound containing atoms selected from the group consisting of one or more of the following elements oxygen, fluorine, or chlorine can be an effective finishing aid. A compound containing atoms selected from the group consisting of at least two of the following elements oxygen, fluorine, nitrogen, or chlorine can be a more preferred lubricant. A synthetic organic polymer containing atoms selected from the group consisting of one or more of the following elements oxygen, fluorine, or chlorine can be an effective finishing aid. A synthetic organic polymer containing atoms selected from the group consisting of at least two of the following elements oxygen, fluorine, nitrogen, or chlorine can be a more preferred lubricant. A sulfated vegetable oil and sulfurized fatty acid soaps are preferred examples of a sulfur containing compound. A lubricant which reacts physically with at least a portion of the workpiece surface being finished is a preferred lubricant. A lubricant which reacts chemically with at least a portion of the workpiece surface being finished is often a more preferred lubricant because it is often a more effective lubricant and can also aid at times directly in the finishing.
A marginally effective lubricant between the workpiece being finished and the finishing element finishing surface is preferred. As used herein, a marginally effective lubricant is a lubricant and amount which does not perfectly lubricant and stop all wear but allows some wear while reducing or eliminating especially deleterious wear.
Limited zone lubrication between the workpiece being finished and the finishing element finishing surface is preferred. As used herein, limited zone lubricating is lubricating to reduce friction between two surfaces while simultaneously having wear occur. Limited zone lubricating which simultaneously reduces friction between the operative finishing interface while maintaining a cut rate on the workpiece surface being finished is preferred. Limited zone lubricating which simultaneously reduces friction between the operative finishing interface while maintaining an acceptable cut rate on the workpiece surface being finished is more preferred. Limited zone lubricating which simultaneously reduces friction between the operative finishing interface while maintaining a finishing rate on the workpiece surface being finished is preferred. Limited zone lubricating which simultaneously reduces friction between the operative finishing interface while maintaining an acceptable finishing rate on the workpiece surface being finished is more preferred. Limited zone lubricating which simultaneously reduces friction between the operative finishing interface while maintaining a planarizing rate on the workpiece surface being finished is preferred. Limited zone lubricating which simultaneously reduces friction between the operative finishing interface while maintaining an acceptable planarizing rate on the workpiece surface being finished is more preferred. Limited zone lubricating which simultaneously reduces friction between the operative finishing interface while maintaining a polishing rate on the workpiece surface being finished is preferred. Limited zone lubricating which simultaneously reduces friction between the operative finishing interface while maintaining an acceptable polishing rate on the workpiece surface being finished is preferred. Lubricant types and concentrations are preferably controlled during limited zone lubricating. Limited zone lubricating offers the advantages of controlled wear along with reduced unwanted surface damage.
Lubricants which are polymeric can be very effective lubricants. A boundary lubricant comprising organic synthetic polymers are preferred lubricants. Supplying a lubricant to the interface of the workpiece surface being finished and the finishing element finishing surface wherein the lubricant is from 0.1 to 15% by weight of the total fluid between the interface is preferred and from 0.2 to 12% by weight of the total fluid between the interface is more preferred and from 0.3 to 12% by weight of the total fluid between the interface is even more preferred and from 0.3 to 9% by weight of the total fluid between the interface is even more particularly preferred. These preferred ranges are given for general guidance and help to those skilled in the art. Lubricants outside this range are currently believed to be useful but not as economical to use.
A lubricant having a molecular weight of at least 250 is often preferred. A lubricant having functional groups containing elements selected from the group consisting of chlorine, sulfur, and phosphorous is preferred and a boundary lubricant having functional groups containing elements selected from the group chlorine, sulfur, and phosphorous is more preferred. A lubricant comprising a fatty acid substance is a preferred lubricant. An preferred example of a fatty substance is a fatty acid ester or salt. Fatty acid salts of plant origin can be particularly preferred. A lubricant comprising a synthetic polymer is preferred and a lubricant comprising a boundary lubricant synthetic polymer is more preferred and a lubricant comprising a boundary lubricant synthetic polymer and wherein the synthetic polymer is water soluble is even more preferred. A polymer having a number average molecular weight from 400 to 150,000 is preferred and having a number average molecular weight from 1,000 to 100,000 is more preferred and having a number average molecular weight from 1,000 to 50,000 is even more preferred.
A lubricant comprising a polyalkylene glycol polymer is a preferred composition. A polymer of polyoxyalkylene glycol monoacrylate or polyoxyalkylene glycol monomethacrylate is very useful as a base of lubricant. A polyethylene glycol having a molecular weight of 200 to 2000 is preferred. Polyglycol having a molecular weight of at least 600 is preferred and a polygylcol having a molecular weight above 800 is more preferred. Polyglycols selected from the group polymers consisting of ethylene oxide, propylene oxide, and butylene oxide and mixtures thereof are particularly preferred. A fatty acid ester can be an effective lubricant. Polyglycol derivatives are also preferred. An amine modified polyglycol is an example of a preferred polyglycol.
A preferred finishing aid can be a lubricating aid which can be included in the finishing element. A finishing aid distributed in at least a portion of the finishing element proximate the finishing element finishing surface is preferred and a finishing aid distributed substantially uniformly in at least a portion of the finishing element proximate the finishing element finishing surface is more preferred and a finishing aid distributed uniformly in at least a portion of the finishing element proximate the finishing element finishing surface is even more preferred. A finishing aid selected from the group consisting of liquid and solid lubricants and mixtures thereof is a preferred finishing aid.
A combination of a liquid lubricant and ethylene vinyl acetate, particularly ethylene vinyl acetate with 15 to 50% vinyl acetate by weight, can be a preferred effective lubricating aid additive. Preferred liquid lubricants include paraffin of the type which are solid at normal room temperature and which become liquid during the production of the finishing element. Typical examples of desirable liquid lubricants include paraffin, naphthene, and aromatic type oils, e.g. mono- and polyalcohol esters of organic and inorganic acids such as monobasic fatty acids, dibasic fatty acids, phthalic acid and phosphoric acid.
The lubricating aid can be contained in finishing element body in different preferred forms. A lubricating aid dispersed in an organic synthetic polymer is preferred. A lubricating aid which is a liquid lubricant can be dispersed throughout the primary organic synthetic resin wherein the liquid lubricant effect of the binding of the fixed abrasive is carefully controlled. A fixed abrasive free a coating having finishing aids is preferred and fixed abrasive particles free of a coating having finishing aid is more preferred. A lubricating aid dispersed in a minor amount of organic synthetic polymer which is itself dispersed in the primary organic synthetic polymer in discrete, unconnected regions is more preferred. As an illustrative example, a lubricant dispersed in a minor amount of an ethylene vinyl acetate and wherein the ethylene vinyl acetate is dispersed in discrete, unconnected regions in a polyacetal resin. A lubricating aid dispersed in discrete, unconnected regions in an organic synthetic polymer is preferred. By dispersing the finishing aid and/or lubricating aids in a plurality of discrete, unconnected regions, their impact on the binding of the fixed abrasive in the body of the fixed abrasive element is reduced or eliminated.
A polyglycol is an example of a preferred finishing aid. Preferred polyglycols include glycols selected from the group consisting of polyethylene glycol, an ethylene oxide-propylene butyl ethers, a diethylene glycol butyl ethers, ethylene oxide-propylene oxide polyglycol, a propylene glycol butyl ether, and polyol esters. A mixture of polyglycols is a preferred finishing aid. Alkoxy ethers of polyalkyl glycols are preferred finishing aids. An ultra high molecular weight polyethylene, particularly in particulate form, is an example of preferred finishing aid. A fluorocarbon resin is an example of a preferred lubricating agent. Fluorocarbons selected from the group consisting of polytetrafluoroethylene (PTFE), ethylene tetrafluoride/propylene hexafluoride copolymer resin (FEP), an ethylene tetrafluoride/perfluoroalkoxyethylene copolymer resin (PFA), an ethylene tetra fluoride/ethylene copolymer resin, a trifluorochloroethylene copolymer resin (PCTFE), and a vinylidene fluoride resin are examples of preferred fluorocarbon resin finishing aids. A polyphenylene sulfide polymer is a preferred polymeric lubricating aid. Polytetrafluoroethylene is a preferred finishing aid. Polytetrafluoroethylene in particulate form is a more preferred finishing aid and polytetrafluoroethylene in particulate form which resists reaggolmeration is a even more preferred finishing aid. A silicone oil is a preferred finishing aid. A polypropylene is a preferred finishing aid, particularly when blended with polyamide and more preferably a nylon 66. A lubricating oil is a preferred finishing aid. A polyolefin polymer can be a preferred effective lubricating aid, particularly when incorporated into polyamide resins and elastomers. A high density polyethylene polymer is a preferred polyolefin resin. A polyolefin/polytetrafluoroethylene blend is also a preferred lubricating aid. Low density polyethylene can be a preferred lubricating aid. A fatty acid substance can be a preferred lubricating aid. An examples of a preferred fatty acid substance is a fatty ester derived from a fatty acid and a polyhydric alcohol. Examples fatty acids used to make the fatty ester are lauric acid, tridecylic acid, myristic acid, pentadecylic acid, palmitic acid, margaric acid, stearic acid, nonadecylic acid, arachidic acid, oleic acid, elaidic acid and other related naturally occurring fatty acids and mixtures thereof Examples of preferred polyhydric alcohols include ethylene glycol, propylene glycol, homopolymers of ethylene glycol and propylene glycol or polymers and copolymers thereof and mixtures thereof.
Illustrative, nonlimiting examples of finishing aids include organic synthetic resin systems and general useful related technology are given in the U.S. Pat. No. 3,287,288 to Reilling, U.S. Pat. No. 3,458,596 to Eaigle, U.S. Pat. No. 4,877,813 to Jimo et. al., U.S. Pat. No. 5,079,287 to Takeshi et. al., U.S. Pat. No. 5,110,685 to Cross et. al., U.S. Pat. No. 5,216,079 to Crosby et. al., U.S. Pat. No. 5,523,352 to Janssen, and U.S. Pat. No. 5,591,808 to Jamison and are included herein by reference in their entirety for guidance and modification as appropriate by those skilled in the art. Still further non limiting illustrative examples of lubricating systems, and/or boundary lubricants are included in U.S. Pat. No. 4,180,532 to Chakrabarti et. al., U.S. Pat. No. 4,212,750 to Gorman, U.S. Pat. No. 4,332,689 to Tanizaki, U.S. Pat. No. 4,379,063 to Williams, U.S. Pat. No. 4,383,937 to Williams, U.S. Pat. No. 4,522,733 to Jonnes, U.S. Pat. No. 4,544,377 to Schwen, U.S. Pat. No. 4,636,321 to Kipp et. al., U.S. Pat. No. 4,767,554 to Malito et. al., U.S. Pat. No. 4,950,415 to Malito, U.S. Pat. No. 5,225,249 to Biresaw, U.S. Pat. No. 5,368,757 to King, U.S. Pat. No. 5,401,428 to Kalota, U.S. Pat. No. 5,433,873 to Camenzind, U.S. Pat. No. 5,545,481 to Harrington, U.S. Pat. No. 5,496,479 to Videau et. al., U.S. Pat. No. 5,5773,146 to Lawton, U.S. Pat. No. 5,614,482 to Baker et. al., U.S. Pat. No. 5,696,061 to Walsh and are included for guidance and modification by those skilled in the art and are included by reference in their entirety herein. Further illustrative examples of aqueous lubricating compositions are included in U.S. Pat. No. 4,619,703 to Gerber, U.S. Pat. No. 4,996,259 to Koehler, U.S. Pat. No. 5,326,381 to Wu, U.S. Pat. No. 5,389,136 to Danner, U.S. Pat. No. 5,601,746 to Danner et. al., U.S. Pat. No. 5,743,949 to Kainz, and U.S. Pat. No. 5,750,606 to Miura et. al are included for guidance and modification by those skilled in the art and are included by reference in their entirety herein. Some preferred suppliers of lubricants include Dow Chemical, Huntsman Corporation, and Chevron Corporation.
Generally those skilled in the art know how to measure the kinetic coefficient of friction. A preferred method is ASTM D 3028-95 and ASTM D 3028-95 B is particularly preferred. Those skilled in the art can modify ASTM D 3028-95 B to adjust to appropriate finishing velocities and to properly take into consideration appropriate fluid effects due to the lubricant and finishing composition. Preferred lubricants and finishing compositions do not corrode the workpiece or localized regions of the workpiece. Corrosion can lead to workpiece failure even before the part is in service. ASTM D 130 is a is a useful test for screening lubricants for particular workpieces and workpiece compositions. As an example of a metal strip such as a copper strip is cleaned and polished so that no discoloration or blemishes detectable. The finishing composition to be tested is then added to a test tube, the copper strip is immersed in the finishing composition and the test tube is then closed with a vented stopper. The test tube is then heated under controlled conditions for a set period of time, the metal strip is removed, the finishing composition removed, and the metal strip is compared to standards processed under identical conditions to judge the corrosive nature and acceptableness of the finishing composition. ASTM D 1748 can also be used to screen for corrosion. Alternately a solid lubricant can be deposited on a surface to be screened for corrosive effects and the target sample tested under appropriate conditions. These test methods are included herein by reference in their entirety.
Supplying an effective marginal lubrication to the interface between the workpiece surface being finished and the finishing element finishing surface is preferred and supplying an effective marginal boundary lubrication to the interface between the workpiece surface being finished and the finishing element finishing surface is more preferred. Marginal lubrication is less than complete lubrication and facilitates controlling frictional wear and tribochemical reactions. An abrasive finishing surface capable of inducing frictional wear to the workpiece surface being finished is preferred and a finishing element, preferably an abrasive finishing surface, capable of inducing tribochemical reactions on the workpiece surface during finishing is also preferred. A wear inducing finishing surface capable of inducing frictional wear to the workpiece surface being finished is even more preferred and a wear inducing finishing surface capable of inducing tribochemical reactions on the workpiece surface during finishing is also even more preferred. A wear inducing finishing surface capable of inducing plastic deformation of a workpiece surface comprised of a polymer is preferred and a wear inducing finishing surface capable of inducing plastic deformation of a workpiece surface comprised at least in part of an organic synthetic polymer is more preferred. Independent control of the lubricant control parameters aids in controlling an effective amount of marginal lubrication and in situ control of the lubricant control parameters is more preferred.
Stabilizing Fillers
A fibrous filler is a preferred stabilizing filler for the finishing element finishing surface layer of this invention. A plurality of synthetic fibers are particularly preferred fibrous filler. Fibrous fillers tend to help generate a lower abrasion coefficient and/or stabilize the finishing element finishing surface from excessive wear. By reducing wear the finishing element has improved stability during finishing.
A preferred stabilizing filler is a dispersion of fibrous filler material dispersed in the finishing element body. An organic synthetic resin fibers are a preferred fibrous filler. Preferred fibrous fillers include fibers selected from the group consisting of aramid fibers, polyester fibers, and polyamide fibers. Preferably the fibers have a fiber diameter of from 1 to 15 microns and more preferably, from 1 to 8 microns. Preferably the fibers have a length of less than 1 cm and more preferably a length from 0.1 to 0.6 cm and even more preferably a length from 0.1 to 0.3 cm. Particularly preferred are short organic synthetic resin fibers that can be dispersed in the finishing element and more preferably mechanically dispersed in at least a portion of the finishing element proximate the finishing element finishing surface and more preferably, mechanically substantially uniformly dispersed in at least a portion of the finishing element proximate the finishing element finishing surface and even more preferably and even more preferably, mechanically substantially uniformly dispersed in at least a portion of the finishing element proximate the finishing element finishing surface. The short organic synthetic fibers are added in the form of short fibers substantially free of entanglement and dispersed in the finishing element matrix. Preferably, the short organic synthetic fibers comprise fibers of at most 0.6 cm long and more preferably 0.3 cm long. An aromatic polyamide fiber is particularly preferred. Aromatic polyamide fibers are available under the tradenames of "Kevlar" from DuPont in Wilmington, Del. and "Teijin Comex" from Teijin Co. Ltd. The organic synthetic resin fibers can be dispersed in the synthetic by methods generally known to those skilled in the art. As a nonlimiting example, the cut fibers can be dispersed in a thermoplastic synthetic resin particles of under 20 mesh, dried, and then compounded in a twin screw, counter rotating extruder to form extruded pellets having a size of from 0.2-0.3 cm. Optionally, the pellets can be water cooled, as appropriate. These newly formed thermoplastic pellets having substantially uniform discrete, dispersed, and unconnected fibers can be used to extruded or injection mold a fixed abrasive element of this invention. Aramid powder can also be used to stabilize the finishing element organic synthetic polymers to wear. Organic synthetic resin fibers are preferred because they tend to reduce unwanted scratching to the workpiece surface.
U.S. Pat. No. 4,877,813 to Jimmo, U.S. Pat. No. 5,079,289 to Takeshi et. al., and U.S. Pat. No. 5,523,352 to Janssen are included herein by reference in its entirety for general guidance and appropriate modification by those skilled in the art.
Workpiece
A workpiece needing finishing is preferred. A homogeneous surface composition is a workpiece surface having one composition throughout and is preferred for some applications. A workpiece needing polishing is preferred. A workpiece needing planarizing is especially preferred. A workpiece having a microelectronic surface is preferred. A workpiece surface having a heterogeneous surface composition is preferred. A heterogeneous surface composition has different regions with different compositions on the surface, further the heterogeneous composition can change with the distance from the surface. Thus finishing can be used for a single workpiece whose surface composition changes as the finishing process progresses. A workpiece having a microelectronic surface having both conductive regions and nonconductive regions is more preferred and is an example of a preferred heterogeneous workpiece surface. Illustrative examples of conductive regions can be regions having copper or tungsten and other known conductors, especially metallic conductors. Metallic conductive regions in the workpiece surface consisting of metals selected from the group consisting of copper, aluminum, and tungsten or combinations thereof are particularly preferred. A semiconductor wafer surface having a repeating pattern of reflective surfaces can be a preferred workpiece surface. A wafer die having a repeating pattern of reflective surfaces can be a preferred workpiece surface. A semiconductor device is a preferred workpiece. A substrate wafer is a preferred workpiece. A semiconductor wafer having a polymeric layer requiring finishing is preferred because a lubricating aid can be particularly helpful in reducing unwanted surface damage to the softer polymeric surfaces. An example of a preferred polymer is a polyimide. Polyimide polymers are commercially available from E. I. DuPont Co. in Wilmington, Del. A semiconductor having a interlayer dielectric needing finishing is preferred.
This invention is particularly preferred for workpieces requiring a highly flat surface. Finishing a workpiece surface to a surface to meet the specified semiconductor industry circuit design rule is preferred and finishing a workpiece surface to a surface to meet the 0.35 micrometers feature size semiconductor design rule is more preferred and finishing a workpiece surface to a surface to meet the 0.25 micrometers feature size semiconductor design rule is even more preferred and finishing a workpiece surface to a to meet the 0.18 micrometers semiconductor design rule is even more particularly preferred. An electronic wafer finished to meet a required surface flatness of the wafer device rule in to be used in the manufacture of ULSIs (Ultra Large Scale Integrated Circuits) is a particularly preferred workpiece made with a method according to preferred embodiments of this invention. The design rules for semiconductors are generally known to those skilled in the art. Guidance can also be found in the "The National Technology Roadmap for Semiconductors" published by SEMATECH in Austin, Tex.
A semiconductor wafer having a diameter of at least 200 mm is preferred and a semiconductor wafer having a diameter of at least 300 mm is more preferred.
For finishing of semiconductor wafers having low-k dielectric layers (low dielectric constant layers), finishing aids, more preferably lubricating aids, are preferred. Illustrative nonlimiting examples of low-k dielectrics are low-k polymeric materials, low-k porous materials, and low-k foam materials. As used herein, a low-k dielectric has at most a k range of less than 3.5 and more preferably less than 3.0 and even more preferably less than 2.5 and even more especially preferred is less than 2∅ Illustrative examples include doped oxides, organic polymers, fluorinated polymers, highly fluorinated organic polymers, and porous materials. Low-k dielectric materials are generally known to those skilled in the semiconductor wafer arts. Abrasive organic synthetic resin particles can be effective to finishing low-dielectric materials. Abrasive organic synthetic resin asperities can be effective to finishing low-dielectric materials. Multilevel semiconductor wafers such as those having low-k dielectric layers and multilevel metal layers are generally known by those skilled in the semiconductor arts and U.S. Pat. No. 6,153,833 to Dawson et al. is included herein by reference for general non-limiting guidance for those skilled in the art. Since low-k dielectric layers generally have lower mechanical strength, the lower coefficient of friction that is offered by organic lubricating boundary layers is particularly preferred. A semiconductor wafer having a plurality of low-k dielectric layers is a preferred workpiece and a semiconductor wafer having at least 3 of low-k dielectric layers is a more preferred workpiece and a semiconductor wafer having at least 5 of low-k dielectric layers is an even more preferred workpiece. Supplying a lubricant to a plurality of the low-k dielectric layers during finishing of the same semiconductor wafer is preferred and supplying a lubricant to at least 3 of the low-k dielectric layers during finishing of the same semiconductor wafer is more preferred and supplying a lubricant to at least 5 of the low-k dielectric layers during finishing of the same semiconductor wafer is even more preferred. A semiconductor wafer having at most 10 low-k dielectric layers is currently preferred but in the future this can increase. Semiconductor wafers for logic integrated circuits are particularly preferred. Defects caused during finishing can be reduced by supplying a lubricant.
A semiconductor wafer having a plurality of metal layers is a preferred workpiece and a semiconductor wafer having at least 3 of metal layers is a more preferred workpiece and a semiconductor wafer having at least 5 of metal layers is an even more preferred workpiece. A semiconductor wafer having at most 10 metal layers is currently preferred but in the future this will increase. A semiconductor wafer having a plurality of information conducting layers is a preferred workpiece and a semiconductor wafer having at least 3 of information conducting layers is a more preferred workpiece and a semiconductor wafer having at least 5 of information conducting layers is an even more preferred workpiece. A semiconductor wafer having at most 10 information conducting layers is currently preferred but in the future this will increase. Current metal wire patterns on a layer of an integrated circuit is a preferred example of information conducting layer. A metal layer for information conducting is preferred. Metal wire patterns and current metal wire patterns in a layer of an integrated circuit are generally known in the semiconductor art.
A semiconductor wafer having logic chips or logic die is particularly preferred because they can have multiple metal layers for supplying lubricants such as preferred lubricants during finishing. Supplying a lubricant to a plurality of finishing layers of the same semiconductor wafer is preferred and supplying a lubricant to at least 3 of finishing layers of the same semiconductor wafer is more preferred and supplying a lubricant to at least 5 of finishing layers of the same semiconductor wafer is more preferred. Defects caused during finishing can be reduced by supplying a lubricant. Further, defects in the first finished layer can cause defects in the second finished layer (and so on). Thus by supplying a lubricant during finishing, one can improve yields by minimizing unwanted defects in both the current and subsequent layers. A method which updates the cost of manufacture control parameters, look-up tables, algorithms, or control logic consistent with the current manufacturing step is preferred. A method which updates finishing recipes for the current manufacturing step is preferred. A method which updates process control parameters for the current manufacturing step is preferred. The semiconductor wafer can be tracked for each finishing step during processing with a tracking means such as tracking code. As an illustrative example, a semiconductor wafer can be assigned with a trackable UPC code. U.S. Pat. No. 5,537,325 issued to Iwakiri, et al., on Jul. 16, 1997 teaches a method to mark and track semiconductor wafers sliced from an ingot through the manufacturing process and is included by reference in its entirety for general guidance and appropriate modification by those skilled in the art. As a nonlimiting example, Cognex Corporation in Natick, Mass. markets commercial tacking means for tracking semiconductor wafers. As further illustration of preferred tracking codes include 2D matrix (such as SEMI 2D matrix), alphanumeric, and bar codes. Processes, performance, and preferred lubrication conditions and information can be tracked and stored by wafer (and/or wafer batches) with this technology when used with the new disclosures herein.
A function layer comprising a metal can be a preferred function layer. Tungsten, tantalum, aluminum, titanium, molybdenum, zinc, hafnium, niobium, copper, and gold represent illustrative nonlimiting examples of thin film function layers comprising of preferred metals. A function layer comprising an oxide can be a preferred function layer. Tantalum pentoxide, aluminum oxide, titanium oxide, niobium pentoxide, zirconium oxide, hafnium oxide zinc oxide, molybdenum oxide, manganese oxide, tin oxide, indium oxide, tungsten oxide, and silicon dioxide comprise illustrative non limiting examples of a function layer comprising an oxide. A function layer comprising a nitride is a preferred function layer. Tungsten nitride, tantalum nitride, aluminum nitride, titanium nitride, silicon nitride, gallium nitride comprise illustrative non limiting examples of a function layer comprising an nitride. A function layer comprised of intermetallic material can be preferred.
U.S. Pat. No. 6,174,377 to Doering et al., U.S. Pat. No. 6,200,893 to Sneh, U.S. Pat. No. 6,228,759 to Wang et. al. and U.S. Publication No. 2001/0040236 A1 are included by reference in their entirety for general guidance on the use, manufacture, and compositions of some useful thin films in semiconductor wafer manufacture and can be modified by those skilled in the semiconductor wafer arts to produce various useful semiconductor wafer die.
Finishing a function layer with an organic lubricating film which self-assembles on the function layer during finishing is preferred. Finishing a function layer with an organic lubricating film which self-assembles on and adheres to a function layer having surface area which changes in real time during finishing is more preferred. Controlling finishing of a function layer with an organic lubricating film which self-assembles on and adheres to a function layer having surface area which changes in real time during finishing by changing the coefficient of friction during finishing is even more preferred.
A semiconductor wafer having logic chips is preferred. A semiconductor wafer having memory chips is preferred. A DRAM is a preferred memory chip. An SRAM is a preferred memory chip. A digital signal processor (DSP) is a preferred semiconductor chip. A microprocessor is a preferred semiconductor chip. Telecommunications chips are a preferred semiconductor chip. A semiconductor chip having a plurality of metal layers is a preferred semiconductor chip. An optoelectronic chip is a preferred semiconductor chip. An SOC (System On a Chip) is a preferred semiconductor chip. A semiconductor wafer planarized in a foundry having manufacturing multiple types of semiconductor wafers is also preferred. Semiconductor chips are generally known to those skilled in the art. As non-limiting example U.S. Pat. No. 6,150,190 to Stankus is included herein by reference in its entirety along with other planarizing references for guidance and modification by those skilled in the art. These foundaries generally have complex product lines and improvements to the cost of manufacture is very helpful in getting and/or retaining customers. Each of these semiconductor chips have multiple processing steps including various planarizing steps during manufacture and generally reducing the cost of manufacture and/or improving performance at the same cost will are expected to enhance profits for the manufacturer.
Finishing Composition
Finishing compositions are generally known. Finishing compositions such as a slurry can have particles. Finishing compositions can be free of abrasive particles. A chemical mechanical polishing slurry can also be used as finishing composition. Alternately, a finishing composition can be modified by those skilled in the art by removing the abrasive particles to form a finishing composition free of abrasive particles. A finishing composition substantially free of abrasive particles is preferred and a finishing composition free of abrasive particles is more preferred. Finishing compositions have their pH adjusted carefully, and generally comprise other chemical additives are used to effect chemical reactions and/other surface changes to the workpiece. A finishing composition having dissolved chemical additives is particularly preferred. Illustrative examples preferred dissolved chemical additives include dissolved acids, bases, buffers, oxidizing agents, reducing agents, stabilizers, and chemical reagents. A finishing composition having a chemical which substantially reacts with material from the workpiece surface being finished is particularly preferred. A finishing composition having a chemical which selectively chemically reacts with only a portion of the workpiece surface is particularly preferred. A finishing composition having a chemical which preferentially chemically reacts with only a portion of the workpiece surface is particularly preferred.
Some illustrative nonlimiting examples of polishing slurries which can be used and/or modified by those skilled in the art are now discussed. An example slurry comprises water, a solid abrasive material and a third component selected from the group consisting of HNO3, H2SO4, and AgNO3 or mixtures thereof Another polishing slurry comprises water, aluminum oxide, and hydrogen peroxide mixed into a slurry. Other chemicals such as KOH (potassium hydroxide) can also be added to the above polishing slurry. Still another illustrative polishing slurry comprises H3PO4 at from about 0.1% to about 20% by volume, H2O2 at from 1% to about 30% by volume, water, and solid abrasive material. Still another polishing slurry comprises an oxidizing agent such as potassium ferricyanide, an abrasive such as silica, and has a pH of between 2 and 4. Still another polishing slurry comprises high purity fine metal oxides particles uniformly dispersed in a stable aqueous medium. Still another polishing slurry comprises a colloidal suspension of SiO2 particles having an average particle size of between 20 and 50 nanometers in alkali solution, demineralized water, and a chemical activator. Energy change sensors are a preferred type of sensor for feed back of in situ control information. U.S. Pat. No. 5,209,816 to Yu et. al. issued in 1993, U.S. Pat. No. 5,354,490 to Yu et. al. issued in 1994, U.S. Pat. No. 5,540,810 to Sandhu et. al. issued in 1996, U.S. Pat. No. 5,516,346 to Cadien et. al. issued in 1996, U.S. Pat. No. 5,527,423 to Neville et. al. issued in 1996, U.S. Pat. No. 5,622,525 to Haisma et. al. issued in 1997, and U.S. Pat. No. 5,645,736 to Allman issued in 1997 comprise illustrative nonlimiting examples of slurries contained herein by reference in their entirety for further general guidance and modification by those skilled in the arts. Commercial CMP polishing slurries are also available from Rodel Manufacturing Company in Newark, Del. Application WO 98/18159 to Hudson gives general guidance for those skilled in the art for modifying current slurries to produce an abrasive free finishing composition.
In a preferred mode, the finishing composition is free of abrasive particles. However as the fixed abrasive finishing element wears down during finishing, some naturally worn fixed abrasive particles can be liberated from the fixed abrasive finishing element can thus temporarily be present in the finishing composition until drainage or removal.
Operative Finishing Motion
Chemical mechanical finishing during operation has the finishing element in operative finishing motion with the surface of the workpiece being finished. A relative lateral parallel motion of the finishing element to the surface of the workpiece being finished is an operative finishing motion. Lateral parallel motion can be over very short distances or macro-distances. A parallel circular motion of the finishing element finishing surface relative to the workpiece surface being finished can be effective. A tangential finishing motion can also be preferred. U.S. Pat. No. 5,177,908 to Tuttle issued in 1993, U.S. Pat. No. 5,234,867 to Schultz et. al. issued in 1993, U.S. Pat. No. 5,522,965 to Chisholm et. al. issued in 1996, U.S. Pat. No. 5,735,731 to Lee in 1998, and U.S. Pat. No. 5,692,947 to Talieh issued in 1997 comprise illustrative nonlimiting examples of operative finishing motion contained herein by reference in their entirety herein for further general guidance of those skilled in the arts.
Some illustrative nonlimiting examples of preferred operative finishing motions for use in the invention are also discussed. This invention has some particularly preferred operative finishing motions of the workpiece surface being finished and the finishing element finishing surface. Moving the finishing element finishing surface in an operative finishing motion to the workpiece surface being finished is a preferred example of an operative finishing motion. Moving the workpiece surface being finished in an operative finishing motion to the finishing element finishing surface is a preferred example of an operative finishing motion. Moving the finishing element finishing surface in a parallel circular motion to the workpiece surface being finished is a preferred example of an operative finishing motion. Moving the workpiece surface being finished in a parallel circular motion to the finishing element finishing surface is a preferred example of an operative parallel. Moving the finishing element finishing surface in a parallel linear motion to the workpiece surface being finished is a preferred example of an operative finishing motion. Moving the workpiece surface being finished in a parallel linear motion to the finishing element finishing surface is a preferred example of an operative parallel. The operative finishing motion performs a significant amount of the polishing and planarizing in this invention.
High speed finishing of the workpiece surface with fixed abrasive finishing elements can cause surface defects in the workpiece surface being finished at higher than desirable rates because of the higher forces generated. As used herein, high speed finishing involves relative operative motion having an equivalent linear velocity of greater than 300 feet per minute and low speed finishing involves relative operative motion having an equivalent linear velocity of at most 300 feet per minute. An operative finishing motion having a velocity of greater than 300 feet per minute is preferred for high speed finishing. An operative finishing motion having a velocity of at most 300 feet per minute is preferred for low speed finishing. The relative operative speed is measured between the finishing element finishing surface and the workpiece surface being finished. Supplying a lubricating aid between the interface of finishing element finishing surface and the workpiece surface being finished when high speed finishing is preferred to reduce the level of surface defects. Supplying a lubricating aid between the interface of a fixed abrasive cylindrical finishing element and a workpiece surface being finished is a preferred example of high speed finishing. Supplying a lubricating aid between the interface of a fixed abrasive belt finishing element and a workpiece surface being finished is a preferred example of high speed finishing. Nonlimiting illustrative examples of a belt finishing element and a cylindrical finishing element are found in patents U.S. Pat. No. 5,735,731 to Lee and U.S. Pat. No. 5,762,536 to Pant and which can be modified by those skilled in the art as appropriate. U.S. Pat. No. 5,735,731 to Lee and U.S. Pat. No. 5,762,536 to Pant are included herein by reference in their entirety.
Platen
The platen is generally a stiff support structure for the finishing element. The platen surface facing the workpiece surface being finished is parallel to the workpiece surface being planarized and is flat and generally made of metal. The platen reduces flexing of the finishing element by supporting the finishing element, optionally a pressure distributive element can also be used. The platen surface during polishing is in operative finishing motion to the workpiece surface being finished. The platen surface can be static while the workpiece surface being finished is moved in an operative finishing motion. The platen surface can be moved in a parallel motion fashion while the workpiece surface being finished is static. Optionally, both the platen surface and the workpiece being finished can be in motion in a way that creates operative finishing motion between the workpiece and the finishing element. Other types of platens are generally known in the industry and functional.
Base Support Structure
The base support structure forms structure which can indirectly aid in applying pressure to the workpiece surface being finished. It generally forms a support surface for those members attached to it directly or operatively connected to the base support structure. Other types of base support structure are generally known in the industry and functional.
Workpiece Finishing Sensor
A workpiece finishing sensor is a sensor which senses the finishing progress to the workpiece in real time so that an in situ signal can be generated. A workpiece finishing sensor is preferred. A workpiece finishing sensor which facilitates measurement and control of finishing in this invention is preferred. A workpiece finishing sensor probe which generates a signal which can be used cooperatively with the secondary friction sensor signal to improve finishing is more preferred.
The change in friction during finishing can be accomplished using technology generally familiar to those skilled in the art. A change in friction can be detected by rotating the workpiece being finished and the finishing element finishing surface with electric motors and measuring current changes on one or both motors. The current changes related to friction changes can then be used to produce a signal to operate the finishing control subsystem. A change in friction can be detected by rotating the workpiece finishing surface with the finishing element finishing surface with electric motors and measuring power changes on one or both motors. Changes in friction can also be measured with thermal sensors. A thermistor is a non-limiting example of preferred non-optical thermal sensor. A thermal couple is another preferred non-optical thermal sensor. An optical thermal sensor is a preferred thermal sensor. A infrared thermal sensor is a preferred thermal sensor. A sensors to measure friction in workpieces being finished are generally known to those skilled in the art. Non limiting examples methods to measure friction in friction sensor probes are described in the following U.S. Pat. No. 5,069,002 to Sandhu et. al., U.S. Pat. No. 5,196,353 to Sandhu, U.S. Pat. No. 5,308,438 to Cote et. al., U.S. Pat. No. 5,595,562 to Yau et. al., U.S. Pat. No. 5,597,442 to Chen, U.S. Pat. No. 5,643,050 to Chen, and U.S. Pat. No. 5,738,562 to Doan et. al. and are included by reference herein in their entirety for guidance and can be advantageously modified by those skilled in the art for use in this invention. Thermal sensors are available commercially from Terra Universal, Inc. in Anaheim, Calif. and Hart Scientific in American Fork, Utah. Measuring the changes in friction at the interface between the workpiece being finished and the finishing element finishing surface to generate an in situ signal for control is particularly preferred because the it can be effectively combined with the a secondary friction sensor further improve finishing control.
A workpiece finishing sensor for the workpiece being finished is preferred. A sensor for the workpiece being finished selected from the group consisting of friction sensors, thermal sensors, optical sensors, acoustical sensors, and electrical sensors are preferred sensors for the workpiece being finished in this invention. An interferometer is a nonlimiting example of an optical sensor. Workpiece thermal sensors and workpiece friction sensors are non-limiting examples of preferred workpiece friction sensors. As used herein, a workpiece friction sensor can sense the friction between the interface of the workpiece being finished and the finishing element finishing surface during operative finishing motion.
Additional non-limiting preferred examples of workpiece finishing sensors will now be discussed. Preferred optical workpiece finishing sensors are discussed. Preferred non-optical workpiece finishing sensors are also discussed. The endpoint for planarization can be effected by monitoring the ratio of the rate of insulator material removed over a particular pattern feature to the rate of insulator material removal over an area devoid of an underlying pattern. The endpoint can be detected by impinging a laser light onto the workpiece being polished and measuring the reflected light versus the expected reflected light as an measure of the planarization process. A system which includes a device for measuring the electrochemical potential of the slurry during processing which is electrically connected to the slurry, and a device for detecting the endpoint of the process, based on upon the electrochemical potential of the slurry, which is responsive to the electrochemical potential measuring device. Endpoint detection can be determined by an apparatus using an interferometer measuring device to direct at an unpatterned die on the exposed surface of the wafer to detect oxide thickness at that point. A semiconductor substrate and a block of optical quartz are simultaneously polished and an interferometer, in conjunction with a data processing system are then used to monitor the thickness and the polishing rate of the optical block to develop an endpoint detection method. A layer over a patterned semiconductor is polished and analyzed using optical methods to determine the end point. An energy supplying means for supplying prescribed energy to the semiconductor wafer are used to develop a detecting means for detecting a polishing end point tot the polishing of film by detecting a variation of the energy supplied tot the semiconductor wafer. The use of sound waves can be used during chemical mechanical polishing by measuring sound waves emanating from the chemical mechanical polishing action of the substrate against the finishing element. A control subsystem can maintain a wafer count, corresponding to how many wafers are finished and the control subsystem regulates the backside pressure applied to each wafer in accordance with a predetermined function such that the backside pressure increases monotonically as the wafer count increases. The above methods are generally known to those skilled in the art. U.S. Pat. No. 5,081,796 to Schultz, U.S. Pat. No. 5,439,551 to Meikle et al., U.S. Pat. No. 5,461,007 to Kobayashi, U.S. Pat. No. 5,413,941 to Koos et. al., U.S. Pat. No. 5,637,185 Murarka et al., U.S. Pat. No. 5,643,046 Katakabe et al., U.S. Pat. No. 5,643,060 to Sandhu et al., U.S. Pat. No. 5,653,622 to Drill et al., and U.S. Pat. No. 5,705,435 to Chen. are included by reference in their entirety and included herein for general guidance and modification by those skilled in the art.
Changes in lubrication, particularly active lubrication, at the operative finishing interface can significantly affect finishing rates and finishing performance in ways that current workpiece finishing sensors cannot handle as effectively as desired. For instance, current workpiece finishing sensors are less effective for monitoring and controlling multiple real time changes in lubrication, particularly active lubrication, and changes in finishing such as finishing rates. This renders prior art workpiece finishing sensors less effective for lubricating boundary layer for controlling and stopping finishing where friction is adjusted or changed in real time. Secondary friction sensor subsystems as indicated above can help to improve real time control wherein the lubrication is changed during the finishing cycle time. Preferred secondary friction sensors include optical friction sensors and non-optical friction sensors. An optical friction sensor is a preferred friction sensor. Operative secondary friction sensors are preferred. Non-limiting preferred examples of optical friction sensors is an infrared thermal sensing unit such as a infrared camera and a laser adjusted to read minute changes of movement friction sensor probe to a perturbation. A non-optical sensing friction sensor is a preferred friction sensor. Non-limiting preferred examples of non-optical friction sensors include thermistors, thermocouples, diodes, thin conducting films, and thin metallic conducting films. Electrical performance versus temperature such as conductivity, voltage, and resistance is measured. Those skilled in the thermal measurement arts are generally familiar with non-optical thermal sensors and their use. A change in friction can be detected by rotating the friction sensor in operative friction contact with the finishing element finishing surface with electric motors and measuring current changes on one or both motors. The current changes related to friction changes can then be used to produce a signal to operate the friction sensor subsystem. Secondary friction detectors can be used to sense changes in friction and tangential friction forces. Some illustrative secondary friction sensor motions are pulsed direction changes, pulsed pressure changes, continuous motion such as circular, elliptical, and linear. An operative secondary friction sensor motion is an operative secondary friction sensor motion between the secondary friction sensor surface and the finishing element finishing surface. An absolute motion of the secondary friction sensor is preferred. A secondary friction detector comprises a probe that can sense friction at the interface between a material which is separated from the workpiece surface being finished. A preferred secondary friction detector is friction sensor probe. A friction sensor probe comprises a probe that can sense friction at the interface between a material which is separate and unconnected to the workpiece surface being finished and the finishing element finishing surface. Details of secondary friction sensors and their use is found in Provisional Patent Application with PTO Serial No. 60/107,300, filed on the Nov. 6, 1998 and having the title "In Situ Friction Detector for finishing workpieces" and in a Regular Patent Application with PTO Ser. No. 09/435181 filed on Nov. 5, 1999 and having the title "In Situ Friction Detector for finishing semiconductor wafers" and they are included in their entirety by reference for general guidance and modification of those skilled in the art. Where the material changes with depth during the finishing of workpiece being finished, one can monitor friction changes with the secondary friction sensor having dissimilar materials even with active lubrication and therefore readily detect the end point. As an additional example, the finishing rate can be correlated with the instantaneous lubrication at the operative finishing interface, a mathematical equation can be developed to monitor finishing rate with instantaneous lubrication information from the secondary sensor and the processor then in real time calculates finishing rates and indicates the end point to the controller.
Process Control Parameters
Preferred process control parameters include those control parameters which can be changed during processing and affect workpiece finishing. Control of the operative finishing motion is a preferred process control parameter. Examples of preferred operative finishing motions include relative velocity, pressure, and type of motion. Examples of preferred types of operative finishing motion include tangential motion, planar finishing motion, linear motion, vibrating motion, oscillating motion, and orbital motion. Finishing temperature is a preferred process control parameter. Finishing temperature can be controlled by changing the heat supplied to the platen or heat supplied to the finishing composition. Alternately, friction can also change the finishing temperature and can be controlled by changes in lubrication, applied pressure during finishing, and relative operative finishing motion velocity. Changes in lubricant can be effected by changing finishing composition(s) and/or feed rate(s). A preferred group of process control parameters consists of parameters selected from the group consisting of wafer relative velocity, platen velocity, polishing pattern, finishing temperature, force exerted on the operative finishing interface, finishing composition, finishing composition feed rate, and finishing pad conditioning
Processor
A processor is preferred to help evaluate the workpiece finishing sensor information. A processor can be a microprocessor, an ASIC, or some other processing means. Processor preferably has computational and digital capabilities. Non limiting examples of processing information include use of various mathematical equations, calculating specific parameters, memory look-up tables or databases for generating certain parameters such as historical performance or preferred parameters or constants, neural networks, fuzzy logic techniques for systematically computing or obtaining preferred parameter values. Input parameter(s) can include information on current wafers being polished such as uniformity, expected polish rates, preferred lubricants(s), preferred lubricant concentrations, entering film thickness and uniformity, workpiece pattern. Further preferred non-limiting processor capabilities including adding, subtracting, multiplying, dividing, use functions, look-up tables, noise subtraction techniques, comparing signals, and adjusting signals in real time from various inputs and combinations thereof
For multi-layer semiconductors, this information can change from layer to layer. A method which updates the cost of manufacture control parameters, look-up tables, algorithms, or control logic consistent with the current manufacturing step is preferred. The semiconductor wafer tracked for each finishing step during processing with a tracking means such as tracking code is preferred. Updating the processing information with each layer is preferred. Updating the input parameters with each layer is also preferred. Updating for new dielectric layers and metal layers is preferred. A control subsystem capable of updating the input parameters for the particular a particular layer during finishing is preferred. A control subsystem capable of updating the process information for the particular a particular layer during finishing is preferred. By updating the control information, generally more effective finishing can be accomplished.
Use of Information for Feedback, Feedforward, and Controller
A controller can use feedforward control, feedback control, and/or combinations thereof For instance, metrology can determine that a particular layer is different from the normal, perhaps thicker, so the finishing recipe can be changed (such as longer times or higher pressures, lower lubrication, shorter lubrication times, etc.). Controllers to control the finishing of workpieces are generally known in the art. Controllers generally use information at least partially derived from the processor to make changes to the process control parameters. A processor is preferably operatively connected to a sensor to gain current information about the process and the processor is also operatively connected to a controller which preferably controls the finishing control parameters. As used herein, a control subsystem is a combination of an operative sensor operatively connected to a processor which is operatively connected to a controller which in turn can change finishing control parameters. A friction sensor is a preferred operative sensor. A workpiece sensor is a preferred operative sensor. A secondary friction sensor is another example of a preferred operative sensor. A control subsystem having a plurality of operative sensors is preferred and a control subsystem having a plurality of friction sensors is more preferred and a control subsystem having a plurality of friction sensors and workpiece sensor is even more preferred. Integrated circuits for processing information are generally known to those skilled in the semiconductor wafer art. A control subsystem having at least one operative sensor is preferred and a control subsystem having at least two operative sensors is more preferred and a control subsystem having at least three operative sensors is even more preferred. A control subsystem having a plurality of operative friction sensors and a workpiece sensor is a preferred example of a control subsystem having a multiplicity of operative sensors. A control subsystem having access to at least one processor is preferred and at least a plurality of processors is more preferred and at least three processors is even more preferred. As an illustrative example, a first processor can have access to a first grouping of look-up tables and a second processor can have access to a second grouping of look-up tables. Alternately as another illustrative example, a first processor can have access to look-up tables having historic performance and a second processor can have access to the control logic for different manufacturing steps. Preferably, the control subsystem has real time access to tracked information on the workpiece being finished to improve control of finishing control parameters in real time (in situ) during the finishing cycle time (or a portion of the finishing cycle time). These control subsystems can better improve control of finishing particularly where heterogeneous lubrication and/or in situ changes to lubrication are made during the finishing cycle time.
An advantage of preferred embodiments is the additional degree of control it gives to the operator performing planarization and/or polishing. To better utilize this control, the use of feedback information to control the finishing control parameters is preferred and in situ control is more preferred. Controlling the finishing control parameters selected from the group consisting of finishing composition feed rates, finishing composition concentration, operative finishing motion, and operative finishing pressure is preferred to improve control of the finishing of the workpiece surface being finished and in situ control is more particularly preferred. Another preferred example of an finishing control parameter is to use a different finishing element for a different portion the finishing cycle time such as one finishing element for the planarizing cycle time and a different finishing element for the polishing cycle time. Workpiece film thickness, measuring apparatus, and control methods are preferred methods of control. Mathematical algorithms for control based on process performance results can be preferred. An empirically-based process model can be preferred. An empirically based process model developed in least in part on historical performance is preferred. A first principles-based process model can also be used for control. Using at least in part a first principles process model and at least in part an empirically based process model can be preferred for process control. A yield model can also be preferred for process control. A yield model based at least in part on historical performance is currently preferred. A recipe for finishing a semiconductor wafer can also be used. A recipes can be developed and/or modified based on historical performance. Multiple recipes stored in the look-up tables are preferred. A process model, more preferably multiple process models can be stored in the look-up tables. A processor having access to the look-up tables is preferred. Yield model are generally known to those skilled in the semiconductor wafer manufacturing arts. Process models are generally known to those skilled in the semiconductor wafer manufacturing arts. Mathematical equations including those developed based on process results can be used. Finishing uniformity parameters selected from the group consisting of Total Thickness Variation (TTV), Focal plane deviation (FPD), Within-Wafer Non-Uniformity (WIW NU), and surface quality are preferred. Average cut rate is a preferred finishing rate control parameter. Average finishing rate is a preferred finishing rate control parameter. Controlling finishing for at least a portion of the finishing cycle time with a finishing sensor subsystem to adjust in situ at least one finishing control parameter that affect finishing results is a preferred method of control finishing. Information feedback subsystems are generally known to those skilled in the art. Illustrative non limiting examples of wafer process control methods include U.S. Pat. No. 5,483,129 to Sandhu issued in 1996, U.S. Pat. No. 5,483,568 to Yano issued in 1996, U.S. Pat. No. 5,627,123 to Mogi issued in 1997, U.S. Pat. No. 5,653,622 to Drill issued in 1997, U.S. Pat. No. 5,657,123 to Mogi issued in 1997, U.S. Pat. No. 5,667,629 to Pan issued in 1997, and U.S. Pat. No. 5,695,601 to Kodera issued in 1997 are included herein for guidance and modification by those skilled in the art and are included herein by reference in their entirety.
Controlling at least one of the finishing control parameters based on using secondary friction sensor information combined with workpiece finishing sensor information is preferred and controlling at least two of the finishing control parameters using a secondary friction sensor information combined with workpiece finishing sensor information is more preferred. Using an electronic finishing sensor subsystem to control the finishing control parameters is preferred. Feedback information selected from the group consisting of finishing rate information and product quality information such as surface quality information is preferred. Non-limiting preferred examples of process rate information include polishing rate, planarizing rate, and workpiece finished per unit time. Non-limiting preferred examples of quality information include first pass first quality yields, focal plane deviation, total thickness variation, measures of non uniformity. Non-limiting examples particularly preferred for electronics parts include Total Thickness Variation (TTV), Focal plane deviation (FPD), Within-Wafer Non-Uniformity (WIW NU), and surface quality.
Algorithms, memory look-up tables, databases, and methods to solve equations simultaneously are generally known. Statistical methods to monitor manufacturing yields are generally known. The use of some general process models, graphs, equations, mathematical formulas for a given set of input data and can generally be modified by those skilled in the art for new, specific manufacturing conditions as generally taught herein. Methods for predictive control are known. Methods for adaptive control are known. Modeling process methods to aid control are also known. Each of these can be preferred for specific applications. U.S. Pat. No. 5,661,669 to Mozumder, U.S. Pat. No. 5,740,033 to Wassick et al., U.S. Pat. No. 5,759,918 to Hoshizaki , et al., U.S. Pat. No. 6,167,360 to Erickson et al., U.S. Pat. No. 6,169,931 to Runnels, U.S. Pat. No. 6,249,712 to Boiquaye, and U.S. Pat. No. 6,289,508 to Erickson et al. give general examples for predictive control, adaptive control, control using a process model, and dynamic process optimization and are included in their entirety for general examples, guidance, and appropriate modification by those skilled in the art.
Data mining can be accomplished on information used previously for process control. This reduces the cost of creating a new table or database for data mining. Further, the data mining results can be more readily applied to new, advanced process control algorithms. New process control algorithms can be developed by evaluating ramp-up historical information including process control parameters and then applying the new process control algorithm for commercial manufacture. New process control algorithms can be developed by evaluating ramp-up historical information including process control parameters and cost of manufacture parameters and then applying the new process control algorithm for commercial manufacture. New process control algorithms can be developed by evaluating previous historical information including process control parameters and then applying the new process control algorithm for future commercial manufacture. New process control algorithms can be developed by evaluating previous historical information including process control parameters and cost of manufacture parameters and then applying the new process control algorithm for future commercial manufacture. Thus the historical performance which is stored in a look-table is preferably used for a plurality of purposes to reduce the cost of manufacture and/or improved the enterprise profitability. By using the historical information used for initial process control multiple times cost of manufacture modeling, and process control algorithm improvement is accomplished in a new, more effective manner to give a new lower cost result because historical information does not have to be entered twice or more times for this analysis.
In situ process control systems relying on workpiece finishing sensors are generally known to those skilled in the CMP industry. Commercial CMP equipment advertised by Applied Materials and IPEC reference some of this equipment.
Finishing Element Conditioning
A finishing element can be conditioned before use or between the finishing of workpieces. Conditioning a finishing element is generally known in the CMP field and generally comprises changing the finishing element finishing surface in a way to improve the finishing of the workpiece. As an example of conditioning, a finishing element having no basic ability or inadequate ability to absorb or transport a finishing composition can be modified with an abrasive finishing element conditioner to have a new texture and/or surface topography to absorb and transport the finishing composition. As a non-limiting preferred example, an abrasive finishing element conditioner having a mechanical mechanism to create a finishing element finishing surface which more effectively transports the finishing composition is preferred. The abrasive finishing element conditioner having a mechanical mechanism to create a finishing element finishing surface which more effectively absorbs the finishing composition is also preferred. A abrasive finishing element conditioner having a mechanical mechanism comprising a plurality of abrasive points which through controlled abrasion can modify the texture or surface topography of a finishing element finishing surface to improve finishing composition absorption and/or transport is preferred. An abrasive finishing element conditioner having a mechanical mechanism comprising a plurality of abrasive points comprising a plurality of diamonds which through controlled abrasion can modify the texture and/or surface topography of a finishing element finishing surface to improve finishing composition absorption and/or transport is preferred.
Modifying a virgin finishing element finishing surface with a finishing element conditioner before use is generally preferred. Modifying a finishing element finishing surface with a finishing element conditioner a plurality of times is also preferred. conditioning a virgin finishing element finishing surface can improve early finishing performance of the finishing element such as by exposing the lubricants. Modifying a finishing element finishing surface with a finishing element conditioner a plurality of times during it useful life in order to improve the finishing element finishing surface performance over the finishing cycle time by exposing new, unused lubricant, particularly new lubricant particles, is preferred. Conditioning a finishing surface by cleaning is preferred. Nondestructive conditioning is a preferred form of conditioning. Conditioning a finishing element finishing surface a plurality of times during it useful life can keep the finishing element finishing surface performance higher over its useful lifetime by exposing fresh lubricant particles to improve finishing performance is also preferred. Using feedback information, preferably information derived from a friction sensor probes, to select when to modify the finishing element finishing surface with the finishing element conditioner is preferred. Using feedback information, preferably information derived from a friction sensor probe, to optimize the method of modifying the finishing element finishing surface with the finishing element conditioner is more preferred. Use of feedback information is discussed further herein in other sections. When using a fixed abrasive finishing element, a finishing element having three dimensionally dispersed lubricants is preferred because during the finishing element conditioning process, material is often mechanically removed from the finishing element finishing surface and preferably this removal exposes fresh lubricants, particularly lubricant particulates, to improve finishing.
Nonlimiting examples of textures and topographies useful for improving transport and absorption of the finishing composition and/or finishing element conditioners and general use are given in U.S. Pat. No. 5,216,843 to Breivogel, U.S. Pat. No. 5,209,760 to Wiand, U.S. Pat. No. 5,489,233 to Cook et. al., U.S. Pat. No. 5,664,987 to Renteln, U.S. Pat. No. 5,655,951 to Meikle et. al., U.S. Pat. No. 5,665,201 to Sahota, and U.S. Pat. No. 5,782,675 to Southwick and are included herein by reference in their entirety for general background and guidance and modification by those skilled in the art.
Cleaning Composition
After finishing the workpiece such as a electronic wafer, the workpiece generally is carefully cleaned before the next manufacturing process step. A lubricant or abrasive particles remaining on the finished workpiece can cause quality problems later on and yield losses.
A lubricant which can be removed from the finished workpiece surface by supplying a water composition to the finished workpiece is preferred and a lubricant which can be removed from the finished workpiece surface by a hot water composition to the finished workpiece is also preferred. An example of a water composition for cleaning is a water solution comprising water soluble surfactants. An effective amount of lubricant which lowers the surface tension of water to help clean abrasive and other adventitious material from the workpiece surface after finishing is particularly preferred.
A lubricant which can be removed from the finished workpiece surface is preferred for many applications. A lubricant which can be removed from the finished workpiece surface by supplying deionized or pure water to the finished workpiece to substantially remove all of the lubricant is preferred and a lubricant which can be removed from the finished workpiece surface by supplying hot deionized or pure water to the finished workpiece to substantially remove all of the lubricant is also preferred. A lubricant which can be removed from the finished workpiece surface by supplying a deionized or pure water to the finished workpiece to completely remove the lubricant is more preferred and a lubricant which can be removed from the finished workpiece surface by supplying hot deionized or pure water to the finished workpiece in to completely remove the lubricant is also more preferred. Supplying a cleaning composition having a surfactant which removes lubricant from the workpiece surface just polished is a preferred cleaning step. A lubricant which lowers the surface tension of the water and thus helps remove any particles from the finished workpiece surface is preferred.
By using water to remove lubricant, the cleaning steps are lower cost and generally less apt to contaminate other areas of the manufacturing steps. A water cleaning based process is generally compatible with many electronic wafer cleaning process and thus is easier to implement on a commercial scale.
Further Comments on Method of Operation
Some particularly preferred embodiments directed at the method of finishing are now discussed. The interface between the finishing surface finishing element and the workpiece being finished is referred to herein as the operative finishing interface.
Providing an abrasive finishing surface for finishing is preferred and providing an abrasive finishing element having a finishing surface for finishing is more preferred and providing an fixed abrasive finishing surface for finishing is even more preferred and providing an fixed abrasive finishing element having a finishing surface for finishing is even more particularly preferred. Fixed abrasive finishing generally produces less abrasive to clean from the workpiece surface that was finished. Providing the workpiece surface being finished proximate to the finishing surface is preferred and positioning the workpiece surface being finished proximate to the finishing surface is more preferred.
Supplying an operative finishing motion between the workpiece surface being finished and the finishing element finishing surface is preferred and applying an operative finishing motion between the workpiece surface being finished and the finishing element finishing surface is more preferred. The operative finishing motion creates the movement and pressure which supplies the finishing action such as chemical reactions, tribochemical reactions and/or abrasive wear. Applying an operative finishing motion that transfers the finishing aid to the interface between the finishing surface and the workpiece surface being finished is preferred and applying an operative finishing motion that transfers the finishing aid, forming a marginally effective lubricating layer between the finishing surface and the workpiece surface being finished is more preferred and applying an operative finishing motion that transfers the finishing aid, forming a marginally effective lubricating boundary layer between the finishing surface and the workpiece surface being finished is even more preferred. The lubrication at the interface reduces the occurrence of high friction and related workpiece surface damage. Applying an operative finishing motion that transfers the finishing aid, forming a lubricating boundary layer between at least a portion of the finishing surface and the semiconductor wafer surface being finished is preferred and applying an operative finishing motion that transfers the finishing aid, forming a marginally effective lubricating layer between at least a portion of the finishing surface and the semiconductor wafer surface being finished so that abrasive wear occurs to the semiconductor wafer surface being finished is more preferred and applying an operative finishing motion that transfers the finishing aid, forming a marginally effective lubricating boundary layer between at least a portion of the finishing surface and the semiconductor wafer surface being finished so that tribochemical wear occur to the semiconductor wafer surface being finished is even more preferred and applying an operative finishing motion that transfers the finishing aid, differentially lubricating different regions of the heterogeneous semiconductor wafer surface being finished even more particularly preferred. With heterogeneous workpiece surfaces, the potential to differentially lubricate and finish a workpiece surface has high value where the differential lubrication is understood and controlled.
Changing the pressure at the operative finishing interface can change the lubricating boundary layer performance. Changing the motion such as speed or type of motion can change the lubricating boundary layer performance. Changing the pressure applied in the operative finishing interface, either total pressure or regional pressure can change the lubricating boundary layer performance. Changing the temperature in the operative finishing interface, either average or regional temperatures can change the lubricating boundary layer performance. Changing the concentration of the boundary lubricant by changing finishing elements can change the lubricating boundary performance. Changing the chemistry of the boundary lubricant in the finishing element can change the lubricating boundary performance by changing finishing elements during the finishing cycle time can be a lubricating control parameter. Changing the pressure at the operative finishing interface can change the lubricating film performance. Changing the motion such as speed or type of motion can change the lubricating film performance. Changing the pressure applied in the operative finishing interface, either total pressure or regional pressure can change the lubricating film performance. Changing the temperature in the operative finishing interface, either average or regional temperatures can change the lubricating film performance. Changing the concentration of the boundary lubricant by changing finishing elements can change the lubricating boundary performance. Changing the chemistry of the boundary lubricant in the finishing element can change the lubricating boundary performance by changing finishing elements during the finishing cycle time can be a lubricating control parameter. The above parameters comprise preferred lubricating boundary layer and/or lubricating film control parameters and can be used to effect changes in the finishing of the workpiece surface being finished. Changing a lubricating control parameter, more preferably a lubricating boundary layer control parameter, to change the tangential force of friction at the operative finishing interface is preferred and changing a lubricating boundary layer control parameter to change the tangential force of friction at a region in the operative finishing interface is more preferred and changing a lubricating boundary layer control parameter to change the tangential force of friction in at least two regions of the operative finishing interface is even more preferred. Changing a control parameter to change the tangential force of friction at the operative finishing interface is preferred and changing a control parameter to change the tangential force of friction at a region in the operative finishing interface is more preferred and changing a control parameter to change the tangential force of friction in at least two regions of the operative finishing interface is even more preferred. Changing the lubricating boundary control parameters at least once during the finishing cycle time is preferred and changing the lubricating control parameters at least twice during the finishing cycle time is more preferred. Changing the lubricating control parameters, more preferably lubricating boundary layer control parameters in situ is preferred and changing the lubricating control parameters in situ with a subsystem controller is more preferred and changing the lubricating control parameters in situ with a controller based on a secondary friction sensor signal is even more preferred.
Changing the pressure at the operative finishing interface can change the lubricating film performance. Changing the motion such as speed or type of motion can change the lubricating film performance. Changing the pressure applied in the operative finishing interface, either total pressure or regional pressure can change the lubricating film performance. Changing the temperature in the operative finishing interface, either average or regional temperatures can change the lubricating film performance. Changing the concentration of the boundary lubricant by changing finishing elements can change the lubricating boundary performance. Changing the chemistry of the boundary lubricant in the finishing element can change the lubricating boundary performance by changing finishing elements during the finishing cycle time can be a lubricating control parameter. The above parameters comprise preferred lubricating film and/or lubricating film control parameters and can be used to effect changes in the finishing of the workpiece surface being finished. Changing a lubricating film control parameter to change the tangential force of friction at the operative finishing interface is preferred and changing a lubricating film control parameter to change the tangential force of friction at a region in the operative finishing interface is more preferred and changing a lubricating film control parameter to change the tangential force of friction in at least two regions of the operative finishing interface is even more preferred. Changing a control parameter to change the tangential force of friction at the operative finishing interface is preferred and changing a control parameter to change the tangential force of friction at a region in the operative finishing interface is more preferred and changing a control parameter to change the tangential force of friction in at least two regions of the operative finishing interface is even more preferred. Changing the lubricating boundary control parameters at least once during the finishing cycle time is preferred and changing the lubricating control parameters at least twice during the finishing cycle time is more preferred. Changing the lubricating film control parameters in situ is preferred and changing the lubricating film control parameters in situ with a subsystem controller is more preferred and changing the lubricating film control parameters in situ with a controller based on a secondary friction sensor signal is even more preferred.
Changing at least one control parameter in situ is preferred and changing at least one control parameter in situ with a subsystem controller is more preferred and changing at least one control parameter in situ with a controller based on a friction sensor signal is even more preferred. Controlling at least one control parameter in situ is preferred and controlling at least one control parameter in situ with a subsystem controller is more preferred and controlling at least one control parameter in situ with a controller based on a friction sensor signal is even more preferred. Changing at least one lubricating control parameter in situ is preferred and changing at least one lubricating control parameter in situ with a subsystem controller is more preferred and changing at least one lubricating control parameter in situ with a controller based on a secondary friction sensor signal is preferred. Controlling at least one lubricating control parameter in situ is preferred and controlling at least one lubricating control parameter in situ with a subsystem controller is more preferred and controlling at least one lubricating control parameter in situ with a controller based on a secondary friction sensor signal is even more preferred.
Applying higher pressure in the unwanted raised region on the semiconductor wafer surface compared to pressure applied to the region below the unwanted raised region causing the boundary layer lubrication thickness to be less on the unwanted raised region and the boundary lubrication thickness to be greater on at least portion of the semiconductor wafer surface below the raised region is a preferred method for differential finishing rates. Applying higher pressure in the unwanted raised region on the semiconductor wafer surface compared to pressure applied to the region below the unwanted raised region causing the boundary layer lubrication thickness to be less on the unwanted raised region and a higher temperature on the unwanted raised region and the boundary lubrication thickness to be greater on at least portion of the semiconductor wafer surface below the raised region and a lower temperature is more preferred method for differential finishing rates.
Applying an operative finishing motion in the operative finishing interface forming an organic lubricating layer such that a tangential friction force is created in the operative finishing interface which is dependent on lubricant properties other than lubricant viscosity is preferred. Applying an operative finishing motion in the operative finishing interface forming an organic lubricating layer such that a tangential friction force is created in the operative finishing interface which depends on lubricant properties other than lubricant viscosity is preferred. Applying an operative finishing motion in the operative finishing interface forming a differential organic lubricating layer such that a plurality of different tangential friction forces are created in different regions of the operative finishing interface and wherein the plurality of the different tangential friction forces are dependent on lubricant properties other than lubricant viscosity is more preferred. Applying the greater tangential friction force in the unwanted raised region of the semiconductor wafer surface being finished and also applying the lower tangential friction force to a region below and proximate to the unwanted raised region of the semiconductor wafer surface being finished is also more preferred. By creating this type of lubricating layer, finishing of the semiconductor wafer can be accomplished with good finishing rates and reduced unwanted surface defects. Planarization can be improved. Within die nonuniformity can be improved.
A lubrication control parameter is a parameter which affects the lubrication of the operative finishing interface. A boundary lubrication control parameter is a parameter which affects the boundary lubrication in the operative finishing interface. A parameter selected from the group consisting of the lubricant chemistry, lubricant concentration, lubricant transfer rate, operative finishing interface temperature, operative finishing interface pressure, and operative finishing interface motion is a preferred group of lubricating control parameters, more preferably lubricating boundary layer control parameters. A parameter selected from the group consisting of the local lubricant chemistry, local lubricant concentration, local lubricant feed rate, local operative finishing interface temperature, local operative finishing interface pressure, and local operative finishing interface motion is a preferred group of lubricating control parameters and more preferably local lubricating boundary layer control parameters. A local operative finishing interface pressure and local lubricating boundary layer is the local pressure and lubrication as illustrated and described in
Supplying an organic lubricant for a portion of finishing cycle time is preferred. Supplying an organic lubricant for a secondary finishing step after a first finishing step free of lubricant can be preferred. Using two finishing steps, one with lubricant and one free of lubricant can reduce unwanted surface damage when finishing a semiconductor wafer. Using two finishing steps can also increase the finishing rate.
Controlling the thickness of the organic lubricating boundary layer by changing at least one lubrication control parameter in a manner that changes the coefficient of friction in at least two different regions in the operative finishing interface in response to an in situ control signal is preferred. Controlling the thickness of the lubricating film layer, more preferably the lubricating boundary layer by changing at least two process control parameters in situ based on feed back information from a lubrication control subsystem having a friction sensor is also preferred.
Controlling at least once the thickness of the organic lubricating boundary layer which changes the coefficient of friction in the operative finishing interface by changing at least one process control parameter in situ based on feed back information from a control subsystem during the finishing cycle time is preferred. A semiconductor wafer surface having at least a first region wherein the lubricating boundary layer thickness is at most one half the molecular layer thickness compared to the lubricating boundary layer thickness on a second, different region is preferred and a semiconductor wafer surface having at least a first region wherein the lubricating boundary layer thickness is at most one third the molecular layer thickness compared to the lubricating boundary layer thickness on a second, different region is more preferred when controlling the coefficient of friction, particularly when controlling the changes in the coefficient of friction. Controlling the thickness of the organic lubricating boundary layer by changing at least one process control parameter in situ based on feed back information from a control subsystem during the finishing cycle time and wherein the control subsystem tracks and updates the feed back information for finishing a plurality of the metal layers is even more preferred for semiconductor wafers having multiple functional levels.
Controlling the thickness of a lubricating film by changing at least one lubrication control parameter in a manner that changes the coefficient of friction in at least two different regions in the operative finishing interface in response to an in situ control signal is preferred. Controlling the thickness of the lubricating film by changing at least two process control parameters in situ based on feed back information from a lubrication control subsystem having a friction sensor is also preferred. Controlling at least once the thickness of the lubricating film which changes the coefficient of friction in the operative finishing interface by changing at least one process control parameter in situ based on feed back information from a control subsystem during the finishing cycle time is preferred. A semiconductor wafer surface having at least a first region wherein the lubricating film is at most one half the molecular layer thickness compared to the lubricating film thickness on a second, different region is preferred and a semiconductor wafer surface having at least a first region wherein the lubricating film thickness is at most one third the molecular layer thickness compared to the lubricating film on a second, different region is more preferred when controlling the coefficient of friction, particularly when controlling the changes in the coefficient of friction. Controlling the thickness of the lubricating film by changing at least one process control parameter in situ based on feed back information from a control subsystem during the finishing cycle time and wherein the control subsystem tracks and updates the feed back information for finishing a plurality of the metal layers is even more preferred for semiconductor wafers having multiple functional levels. An organic lubricating film is preferred.
A finishing aid selected from the group consisting of a lubricating aid and chemically reactive aid and both being free of an encapsulating films is preferred. A finishing aid which reacts with the workpiece surface being finished is preferred and which reacts with a portion of the workpiece surface being finished is more preferred and which differentially reacts with heterogeneous portions of a workpiece surface being finished is even more preferred. By reacting with the workpiece surface, control of finishing rates can be improved and some surface defects minimized or eliminated. A finishing aid which reduces friction during finishing is also preferred because surface defects can be minimized.
Cleaning the workpiece surface reduces defects in the semiconductor later on in wafer processing.
Supplying a finishing aid to the workpiece surface being finished which changes the rate of a chemical reaction is preferred. Supplying a finishing aid to the workpiece surface being finished which can change the rate of a tribochemical reaction is more preferred. Supplying a finishing aid to a heterogeneous workpiece surface being finished which can change the rate of a plurality of tribochemical reactions is even more preferred (such as on metallic and nonmetallic surface regions). Supplying a finishing aid to the workpiece surface being finished having a property selected from the group consisting of workpiece surface coefficient of friction, workpiece finish rate change, a heterogeneous workpiece surface having differential coefficient of friction, and a heterogeneous workpiece surface having differential finishing rate change which reduces unwanted damage to the workpiece surface is particularly preferred. A tribochemical reaction is a preferred chemical reaction.
Controlling in real time with a control subsystem a finishing property selected from the group consisting of workpiece surface coefficient of friction, workpiece finish rate, and workpiece surface chemical reaction is preferred. Controlling in real time with a control subsystem at least two finishing properties selected from the group consisting of workpiece surface coefficient of friction, workpiece finish rate, and workpiece surface chemical reaction is more preferred. Controlling in real time with a control subsystem at least three finishing properties selected from the group consisting of workpiece surface coefficient of friction, workpiece finish rate, and workpiece surface chemical reaction is even more preferred. Controlling in real time with a control subsystem a regional finishing property of a workpiece selected from the group consisting of workpiece surface coefficient of friction, workpiece finish rate, and workpiece surface chemical reaction is preferred. Controlling in real time with a control subsystem at least two regional finishing properties of a workpiece selected from the group consisting of workpiece surface coefficient of friction, workpiece finish rate, and workpiece surface chemical reaction is more preferred. Controlling in real time with a control subsystem at least three regional finishing properties of a workpiece selected from the group consisting of workpiece surface coefficient of friction, workpiece finish rate, and workpiece surface chemical reaction is even more preferred. A preferred regional finishing property is the finishing rate on a conductive region of a semiconductor wafer surface having both conductive and nonconductive regions. Another preferred regional finishing property is the chemical reaction rate on an unwanted raised region of a semiconductor wafer surface having both unwanted raised regions and lower regions proximate to the unwanted raised regions. Controlling an organic lubricating film is a preferred method to control the coefficient of friction. Controlling an organic lubricating boundary layer is a preferred method to control the coefficient of friction.
Controlling the thickness of at least one organic lubricating film by changing at least one control parameter in a manner that changes the tangential force of friction in at least one regions of the operative finishing interface in response to an in situ control signal is a preferred method of finishing is preferred. Controlling the thickness of at least one organic lubricating film by changing at least one control parameter in a manner that changes the tangential force of friction in at least two different regions of the operative finishing interface in response to an in situ control signal is a more preferred method of finishing. Controlling the thickness of at least one organic lubricating film by changing at least one control parameter in a manner that changes the coefficient of friction in at least one regions of the operative finishing interface in response to an in situ control signal is a preferred method of finishing is even more preferred. Controlling the thickness of at least one organic lubricating film by changing at least one control parameter in a manner that changes the coefficient of friction in at least two different regions of the operative finishing interface in response to an in situ control signal is especially more preferred method of finishing. Finishing can use a plurality of organic lubricants forming a plurality of organic lubricating films. The plurality of organic lubricating films can form a controlled heterogeneous lubrication at the operative interface. For example wherein the workpiece surface has a first uniform region and a second uniform region and the organic lubricating film differentially lubricates the first uniform region and the second uniform region is preferred. An operative control subsystem having a plurality of operative sensors is preferred. Forming a organic lubricating film of a preferred thickness on the conductive region of the semiconductor wafer surface and wherein the organic lubricating film physically or chemically interacts with and adheres to the conductive region on the semiconductor wafer surface is a preferred method of finishing. By finishing with organic lubricating film, preferably a controlled organic lubricating film, improved finishing with generally lower unwanted surface defects can be accomplished.
Using the method of this invention to finish a workpiece, especially a semiconductor wafer, by controlling finishing for a period of time with an operative measurement and control subsystem operatively connected to the finishing equipment control mechanism to adjust in situ at least one finishing control parameter that affect finishing selected from the group consisting of the finishing rate and the finishing uniformity is preferred. Operative connections are generally known to those skilled in the art. Optical fiber connection are an example of a preferred operative connection.
Using the method of this invention to finish a workpiece, especially a semiconductor wafer, by controlling finishing for a period of time with an electronic control subsystem connected electrically to the finishing equipment control mechanism to adjust in situ at least one finishing control parameter that affect finishing selected from the group consisting of the finishing rate and the finishing uniformity is preferred. Finishing control parameters are selected from the group consisting of the finishing composition, finishing composition feed rate, finishing temperature, finishing pressure, operative finishing motion velocity and type, and finishing element type and condition change are preferred. The electronic control subsystem is operatively connected electrically to the lubrication control mechanism. The measurement and control subsystem can be separate units and/or integrated into one unit. A preferred method to measure finishing rate is to measure the change in the amount of material removed in angstroms per unit time in minutes (Å/min). Guidance on the measurement and calculation for polishing rate for semiconductor part is found in U.S. Pat. No. 5,695,601 to Kodera et. al. issued in 1997 and is included herein in its entirety for illustrative guidance.
An average finishing rate range is preferred, particularly for workpieces requiring very high precision finishing such as in process electronic wafers. Average cut rate is used as a preferred metric to describe preferred finishing rates. Average cut rate is metric generally known to those skilled in the art. For electronic workpieces, such as wafers, a cut rate of from 100 to 25,000 Angstroms per minute on at least a portion of the workpiece is preferred and a cut rate of from 200 to 15,000 Angstroms per minute on at least a portion of the workpiece is more preferred and a cut rate of from 500 to 10,000 Angstroms per minute on at least a portion of the workpiece is even more preferred and a cut rate of from 500 to 7,000 Angstroms per minute on at least a portion of the workpiece is even more particularly preferred and a cut rate of from 1,000 to 5,000 Angstroms per minute on at least a portion of the workpiece is most preferred. A finishing rate of at least 100 Angstroms per minute for at least one of the regions on the surface of the workpiece being finished is preferred and a finishing rate of at least 200 Angstroms per minute for at least one of the materials on the surface of the workpiece being finished is preferred and a finishing rate of at least 500 Angstroms per minute for at least one of the regions on the surface of the workpiece being finished is more preferred and a finishing rate of at least 1000 Angstroms per minute for at least one of the regions on the surface of the workpiece being finished is even more preferred where significant removal of a surface region is desired. During finishing there are often regions where the operator desires that the finishing stop when reached such when removing a conductive region (such as a metallic region) over a non conductive region (such as a silicon dioxide region). For regions where it is desirable to stop finishing (such as the silicon dioxide region example above), a finishing rate of at most 1000 Angstroms per minute for at least one of the regions on the surface of the workpiece being finished is preferred and a finishing rate of at most 500 Angstroms per minute for at least one of the materials on the surface of the workpiece being finished is preferred and a finishing rate of at most 200 Angstroms per minute for at least one of the regions on the surface of the workpiece being finished is more preferred and a finishing rate of at most 100 Angstroms per minute for at least one of the regions on the surface of the workpiece is even more preferred where significant removal of a surface region is desired. The finishing rate can be controlled lubricants and with the process control parameters discussed herein.
Using finishing of this invention to remove raised surface perturbations and/or surface imperfections on the workpiece surface being finished is preferred. Using the method of this invention to finish a workpiece, especially a semiconductor wafer, at a planarizing rate and/or planarizing uniformity according to a controllable set of operational parameters that upon variation change the planarizing rate and/or planarizing uniformity and wherein the operational parameters of at least two operational parameters are selected from the group consisting of the type of lubricant, quantity of lubricant, and time period lubrication is preferred. Using the method of this invention to polish a workpiece, especially a semiconductor wafer, wherein an electronic control subsystem connected electrically to an operative lubrication feed mechanism adjusts in situ the subset of operational parameters that affect the planarizing rate and/or the planarizing uniformity and wherein the operational parameters are selected from the group consisting of the type of lubricant, quantity of lubricant, and time period lubrication is preferred. The electronic control subsystem is operatively connected electrically to the operative lubrication feed mechanism.
Using the method of this invention to polish or planarize a workpiece, especially a semiconductor wafer, supplying lubrication moderated by a finishing element having at least two layers is preferred. More preferably the finishing element having at least two layers has a finishing surface layer which has a higher hardness than the subsurface layer. A finishing element having at least two layers has a finishing surface layer which has a lower hardness than the subsurface layer is preferred, particularly for polishing.
A preferred embodiment of this invention is directed to a method of finishing of a semiconductor wafer surface being finished comprising a step 1) of providing a finishing element finishing surface; a step 2) of positioning the semiconductor wafer surface proximate to the finishing surface; a step 3) of providing an organic lubricant proximate to the surface of the semiconductor wafer surface being finished; a step 4) of applying an operative finishing motion in an interface between the semiconductor wafer surface being finished and the finishing element finishing surface; and wherein applying the operative finishing motion forms an organic lubricating film layer of at most 10 molecules thick which self-assembles with and adheres to the semiconductor wafer surface being finished.
A preferred embodiment of this invention is directed to a method of finishing of a semiconductor wafer surface having a first uniform region surface and a second uniform region surface comprising a step 1) of providing an abrasive finishing surface; a step 2) of positioning the semiconductor wafer surface proximate to the abrasive finishing surface; a step 3) of providing an organic lubricant between the abrasive finishing surface and the first and second uniform region surfaces of the semiconductor wafer surface; a step 4) of applying an operative finishing motion that transfers the organic lubricant from the abrasive finishing surface to an interface comprising the abrasive finishing and the first and second uniform region surfaces forming a self-assembling organic lubricating film on at least the first uniform region surface; and a step 5) of controlling the thickness of the organic lubricating film by changing at least one control parameter in a manner that changes the coefficient of friction in at least one of the first and second uniform region surfaces in response to an in situ control signal during at least a portion of the finishing cycle time.
A preferred embodiment of this invention is directed to a method of finishing of a semiconductor wafer surface having a conductive region surface comprising a step 1) of providing an abrasive finishing surface; a step 2) of providing an organic boundary lubricant between the abrasive finishing surface and the conductive region of the semiconductor wafer surface being finished; and a step 3) of applying an operative finishing motion between the semiconductor wafer surface being finished and the abrasive finishing surface forming a organic lubricating film of at most 10 molecules thick on the conductive region of the semiconductor wafer surface wherein the operative finishing motion forms a friction in the interface between the conductive region on the semiconductor wafer surface and the finishing element finishing surface; and the organic lubricating film interacts with and self-assembles with the conductive region surface to reduce the coefficient of friction.
A preferred embodiment of this invention is directed to a method of finishing of a semiconductor wafer surface being finished having uniform regions and a plurality of wafer die, each wafer die having a repeating pattern of unwanted raised regions, the method comprising a step 1) of providing an abrasive finishing element finishing surface; a step 2) of providing an organic lubricant to an interface between the abrasive finishing element finishing surface and the semiconductor wafer surface being finished; and a step 3) of applying an operative finishing motion to the interface between the abrasive finishing element finishing surface and the semiconductor wafer surface being finished forming a self-assembling organic lubricating film with a thickness of at most 6 molecules on at least a portion of the semiconductor wafer surface being finished.
A preferred embodiment of this invention is directed to a method of finishing of a semiconductor wafer surface being finished having uniform regions having a plurality of unwanted raised regions, the method comprising a step 1) of providing an abrasive finishing element finishing surface; a step 2) of providing an organic lubricant to an interface between the semiconductor wafer surface and the finishing element finishing surface; and a step 3) of applying an operative finishing motion forming a marginal organic lubricating film on at least a portion of the semiconductor wafer surface being finished and wherein the operative finishing motion forms a friction in the interface between the uniform regions of the semiconductor wafer surface and the finishing element finishing surface and the organic lubricating film self-assembles with the uniform regions of the semiconductor wafer surface; and a step 4) of controlling the marginal organic lubricating film by changing at least one control parameter in a manner that changes the coefficient of friction in at least two different uniform regions of the interface between the semiconductor wafer surface and the finishing element finishing surface in response to an in situ control signal during at least a portion of the finishing cycle time.
A preferred embodiment of this invention is directed to a method of finishing of a semiconductor wafer surface having a conductive region being finished comprising a step of 1) providing an abrasive finishing element finishing surface; a step 2) of providing an organic boundary lubricant between the abrasive finishing element finishing surface and the conductive region of the semiconductor wafer surface being finished; and a step 3) of applying an operative finishing motion between the semiconductor wafer surface being finished and the abrasive finishing element finishing surface forming a heterogeneous organic lubricating film on the conductive region of the semiconductor wafer surface wherein the operative finishing motion forms a friction in the interface between the conductive region on the semiconductor wafer surface and the finishing element finishing surface, and the organic lubricating film self-assembles on at least a portion of the conductive region on the semiconductor wafer surface and reduces the coefficient of friction on at least a portion of the conductive region, and wherein the semiconductor wafer surface has at least one unwanted raised region wherein the organic lubricating film thickness is less on the unwanted raised region and the organic lubricating film thickness is greater on at least a portion of the semiconductor surface below and proximate to the unwanted raised region.
A preferred embodiment of this invention is directed to a method of finishing of a semiconductor wafer surface having at least two different uniform regions being finished comprising a step 1) of providing a finishing element finishing surface; a step 2) of providing an organic lubricant to an interface between the semiconductor wafer surface and the finishing element finishing surface; and a step 3) of applying an operative finishing motion to the interface between the semiconductor wafer surface and the finishing element finishing surface forming a marginal organic lubricating film and the organic lubricating film adheres to the semiconductor wafer surface and wherein the operative finishing motion forms a friction in the interface between the semiconductor wafer surface and the finishing element finishing surface; and a step 4) of controlling the marginal organic lubricating film by changing at least one control parameter in a manner that changes the coefficient of friction in at least two different uniform regions of the interface between the semiconductor wafer surface and the finishing element finishing surface in response to an in situ control signal during at least a portion of the finishing cycle time; and a step 5) of inducing tribochemical wear to the semiconductor wafer surface being finishing.
A preferred embodiment of this invention is directed to a method of finishing of a semiconductor wafer surface having a first uniform region surface and a second uniform region surface comprising a step 1) of providing a finishing element finishing surface; a step 2) of providing an organic lubricant to an operative finishing interface; a step 3) of applying an operative finishing motion to the interface formed between the finishing element finishing surface and the first and second uniform region surfaces forming a marginal organic lubricating film on at least the first uniform region surface and wherein the operative finishing motion forms a friction in the interface between the semiconductor wafer surface and the finishing element finishing surface and the marginal organic lubricating film self-assembles with and adheres to at least the first uniform region; and a step 4) of controlling the marginal organic lubricating film by changing at least one control parameter in a manner that changes the coefficient of friction in at least the first uniform region in response to an in situ control signal during at least a portion of the finishing cycle time; and a step 5) of inducing differential tribochemical wear to at least a portion of the semiconductor wafer surface.
A preferred embodiment of this invention is directed to a method of finishing of a semiconductor wafer surface having a first uniform region surface and a second uniform region surface comprising a step 1) of providing a finishing element finishing surface; a step 2) of providing an organic lubricant to an operative finishing interface; and a step 3) of applying an operative finishing motion to the interface formed between the finishing element finishing surface and the first and second uniform region surfaces forming a marginal organic lubricating film on the first uniform region surface and the second uniform region surface and wherein the operative finishing motion forms a first friction in the interface between the first uniform region surface and the finishing element finishing surface and a second friction in the interface between the second uniform region surface and the finishing element finishing surface and the marginal organic lubricating film self-assembles with and adheres to the first uniform region surface and the second uniform region surface; a step 4) of controlling the marginal organic lubricating film by changing at least one control parameter in a manner that changes the coefficient of friction in at least the first uniform region in response to an in situ control signal during at least a portion of the finishing cycle time; and a step 5) of inducing differential tribochemical wear to at least a portion of the semiconductor wafer surface.
A preferred embodiment of this invention is directed to a method of finishing of a semiconductor wafer surface having a first uniform region surface and a second uniform region surface comprising a step 1) of providing a finishing surface; a step 2) of providing an organic lubricant to an operative finishing interface; a step 3) of applying an operative finishing motion to the interface formed between the finishing element finishing surface and the first and second uniform region surfaces forming a marginal organic lubricating film on at least the first uniform region surface and wherein the operative finishing motion forms a friction in the interface between the semiconductor wafer surface and the finishing element finishing surface and the marginal organic lubricating film self-assembles with and adheres to at least the first uniform region; and a step 4) of controlling the marginal organic lubricating film by changing at least one control parameter in a manner that changes the coefficient of friction in at least the first uniform region in response to an in situ control signal during at least a portion of the finishing cycle time; and a step 5) of inducing differential chemical reactions to at least a portion of the semiconductor wafer surface.
A preferred embodiment of this invention is directed to a method of finishing of a semiconductor wafer surface having a first uniform region surface and a second uniform region surface comprising a step 1) of providing a finishing element finishing surface; a step 2) of providing an organic lubricant to an operative finishing interface; and a step 3) of applying an operative finishing motion to the interface formed between the finishing element finishing surface and the first and second uniform region surfaces forming a organic lubricating film on the first uniform region surface and the second uniform region surface and wherein the operative finishing motion forms a first friction in the interface between the first uniform region surface and the finishing element finishing surface and a second friction in the interface between the second uniform region surface and the finishing element finishing surface and the organic lubricating film self-assembles with and adheres to the first uniform region surface and the second uniform region surface; a step 4) of controlling the organic lubricating film by changing at least one control parameter in a manner that changes the coefficient of friction in at least the first uniform region in response to an in situ control signal during at least a portion of the finishing cycle time; and a step 5) of inducing differential chemical reactions to at least a portion of the semiconductor wafer surface.
A preferred embodiment of this invention is directed to a method of finishing a semiconductor wafer having a semiconductor wafer surface and a tracking code comprising a step of providing an finishing element finishing surface; a step of providing an organic lubricant to an interface between the finishing element finishing surface and the semiconductor wafer surface; a step of providing a control subsystem having a processor, a plurality of operative sensors, and a controller and wherein the processor has access to access to the tracking code, look-up tables, and a historical performance; a step of applying an operative finishing motion to the interface between the abrasive finishing element finishing surface and the semiconductor wafer surface forming an organic lubricating film with a thickness of from 1-10 molecules thick on at least a portion of the semiconductor wafer surface; a step of sensing a first progress of finishing information with the plurality of operative sensors; a step of determining a change to at least one process control parameter at least in part using the progress of finishing information, the tracking code, look-up tables, and the historical performance; a step of changing the at least one process control parameter; a step of sensing a second progress of finishing information with the plurality of operative sensors after changing the at least one process control parameter; and a step of storing at least in part the first progress of finishing information, the second progress of finishing information, the tracking code, and the historical performance step which was used. The stored information can give valuable information for future process control.
Determining a change to at least one process control parameter at least in part using the progress of finishing information, the tracking code, look-up tables, and the control logic consistent with the current manufacturing step is a preferred step. Determining a change to the at least one control parameter with the control subsystem using at least in part the tracking code, the in situ finishing information, and the control logic consistent with the current manufacturing step before controlling the organic lubricating film is more preferred. Storing at least in part some of the finishing information is preferred. Storing at least in part a first progress of finishing information, if available, the second progress of finishing information, the tracking code, and the control logic consistent with the current manufacturing step after is preferred. Using the stored information to determine a process control parameter for a subsequent finishing step is preferred. As an illustrative example, using the stored information comprising at least in part the first progress of finishing information, the second progress of finishing information, the tracking code, and the control logic consistent with the current manufacturing step which was used for controlling the at least one control parameter for finishing for the second layer is a preferred use of stored information. By storing, using for determining and then control, finishing methods using lubricants can be improved and workpieces can be finished with generally lower unwanted surface damage and/or at a lower cost and/or at a higher throughput rate.
Storing the information used for lubricating process control for future use is preferred. By storing information, preferably electronically, more preferably in look-up tables, the information can be looked-up and used without having to re-enter data with its associated costs and potential for error. Using the stored information to make a change, more preferably an appreciable change, to a process model having an organic lubricating control parameter is preferred. Using the stored information to make a change, more preferably an appreciable change, to a process model having an organic lubricating film control parameter is preferred. Using the stored information to make a change, more preferably an appreciable change, to a process model having a plurality of organic lubricating control parameters is preferred. As an illustrative example, the stored information can be used to modify the Preston Equation in a process model for polishing which is generally known to those skilled in the semiconductor wafer polishing art. The stored information can be used for data mining. Data mining can be used to improve a process model, cost of manufacture, cost of manufacture model, and/or to identify preferred changes to control parameters for improved finishing. The stored information during ramp-up stage can used to improve a commercial stage process model and/or cost of manufacture model. By directly storing information for future use, a multiple valuable uses are made available at reduced cost and with reduced chance for error.
Finishing of a semiconductor wafer surface being finished a finishing element, preferably a fixed abrasive finishing element, having a finishing element surface layer having a lubricating aid therein and a fixed abrasive finishing surface further the fixed abrasive finishing element further having a finishing element subsurface layer free of lubricating aid therein a preferred finishing element. A fixed abrasive finishing element having a finishing element surface layer having a finishing surface, a dispersed lubricating aid, and fixed abrasive elements and the fixed abrasive finishing element further comprising a finishing element subsurface layer free of lubricating aid is more preferred. This can reduce costs in the manufacture of the finishing element by reducing the costs of incorporating the finishing aids such as lubricant throughout the entire thickness. Finishing with a finishing element wherein the finishing element has a uniform dispersed lubricants beyond the useful finishing element finishing surface thick used for finishing is preferred because then lubrication will be stable within a finishing cycle run and from run to run in during finishing of the expensive semiconductor wafers thus helping to reduce yield loss.
As is generally known in the semiconductor wafer art, development of actual preferred embodiments is generally accomplished in stages along with numerous process and design specific information. Given the teachings and guidance contained herein, preferred embodiments are generally implemented in stages while taking into account numerous business, process, and product specific information by those generally skilled in the semiconductor wafer arts. Although the implementation of a preferred embodiment may have generally numerous steps while taking into account the numerous business, process, and product specific information, implementation merely requires routine experimentation and effort given the teachings and guidance contained herein. Thus although the implementation may be somewhat time-consuming, it is nevertheless a generally routine undertaking for those of ordinary skill in the art having the benefit of the information and guidance contained herein.
Applying an operative finishing motion with a finishing entity (entities) to form an organic lubricating boundary layer is preferred. A finishing element is a preferred finishing entity. Abrasive particles comprise preferred finishing entities. A finishing entity (entities) which rub against the semiconductor wafer surface being finished during finishing in the presence of an organic boundary lubricant forming an organic boundary lubricating layer is a preferred embodiment. Applying an operative finishing motion with a finishing entity (entities) to form an organic lubricating film is preferred. Applying an operative finishing motion with a finishing entity (entities) to form a self-assembling organic lubricating film is more preferred. Applying an operative finishing motion with a finishing entity (entities) to form a self-assembling and reassembling organic lubricating film is even more preferred. A finishing element is a preferred finishing entity. Abrasive particles comprise preferred finishing entities. A finishing entity (entities) which rub against the semiconductor wafer surface being finished during finishing in the presence of an organic lubricant forming an organic lubricating film is a preferred embodiment.
Illustrative nonlimiting examples of illustrative and/or useful technology have referenced by their patents numbers and all of these patents are included herein by reference in their entirety for further general guidance and modification by those skilled in the arts. The scope of the invention should be determined by any issued claims and their legal equivalents, rather than by the preferred embodiments and details as discussed herein.
Patent | Priority | Assignee | Title |
6986698, | Apr 01 1999 | SemCon Tech, LLC | Wafer refining |
7037172, | Apr 01 1999 | SemCon Tech, LLC | Advanced wafer planarizing |
7377836, | Oct 10 2000 | SemCon Tech, LLC | Versatile wafer refining |
7514016, | Jul 30 2004 | Western Digital Technologies, INC | Methodology of chemical mechanical nanogrinding for ultra precision finishing of workpieces |
7988534, | May 19 2004 | Optical polishing pitch formulations | |
8210900, | Oct 31 2008 | Applied Materials, Inc.; Applied Materials, Inc | Dishing and defect control of chemical mechanical polishing using real-time adjustable additive delivery |
8231432, | May 19 2004 | Stephen P., Sutton; Elizabeth H., Sutton | Optical polishing pitch formulations |
Patent | Priority | Assignee | Title |
5069002, | Apr 17 1991 | Round Rock Research, LLC | Apparatus for endpoint detection during mechanical planarization of semiconductor wafers |
5107445, | Dec 04 1990 | Luxtron Corporation | Modular luminescence-based measuring system using fast digital signal processing |
5137544, | Apr 10 1990 | Boeing Company, the | Stress-free chemo-mechanical polishing agent for II-VI compound semiconductor single crystals and method of polishing |
5154512, | Apr 10 1990 | LUXTRON CORPORATION, A CORP OF CA | Non-contact techniques for measuring temperature or radiation-heated objects |
5166080, | Apr 29 1991 | Luxtron Corporation | Techniques for measuring the thickness of a film formed on a substrate |
5196353, | Jan 03 1992 | Micron Technology, Inc. | Method for controlling a semiconductor (CMP) process by measuring a surface temperature and developing a thermal image of the wafer |
5308438, | Jan 30 1992 | International Business Machines Corporation | Endpoint detection apparatus and method for chemical/mechanical polishing |
5314843, | Mar 27 1992 | Round Rock Research, LLC | Integrated circuit polishing method |
5340370, | Nov 03 1993 | Micron Technology, Inc | Slurries for chemical mechanical polishing |
5352277, | Dec 12 1988 | MONSANTO P L C | Final polishing composition |
5413941, | Jan 06 1994 | Round Rock Research, LLC | Optical end point detection methods in semiconductor planarizing polishing processes |
5537325, | Oct 29 1991 | Komatsu Electronic Metals Co., Ltd. | Apparatus for and method of manufacturing semiconductor wafer |
5595526, | Nov 30 1994 | Micron Technology, Inc | Method and apparatus for endpoint detection in a chemical/mechanical process for polishing a substrate |
5597442, | Oct 16 1995 | TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY LTD. | Chemical/mechanical planarization (CMP) endpoint method using measurement of polishing pad temperature |
5609511, | Apr 14 1994 | Hitachi, Ltd. | Polishing method |
5609517, | Nov 20 1995 | International Business Machines Corporation | Composite polishing pad |
5614444, | Jun 06 1995 | HEWLETT-PACKARD DEVELOPMENT COMPANY, L P | Method of using additives with silica-based slurries to enhance selectivity in metal CMP |
5639388, | Jan 19 1995 | Ebara Corporation | Polishing endpoint detection method |
5643060, | Aug 25 1993 | Round Rock Research, LLC | System for real-time control of semiconductor wafer polishing including heater |
5647952, | Apr 01 1996 | TRANSPACIFIC IP LTD , | Chemical/mechanical polish (CMP) endpoint method |
5667629, | Jun 21 1996 | Chartered Semiconductor Manufactuing Pte, Ltd. | Method and apparatus for determination of the end point in chemical mechanical polishing |
5685766, | Nov 30 1995 | SpeedFam-IPEC Corporation | Polishing control method |
5695384, | Dec 07 1994 | Texas Instruments Incorporated | Chemical-mechanical polishing salt slurry |
5695660, | Sep 17 1992 | LUMASENSE TECHNOLOGIES HOLDINGS, INC | Optical techniques of measuring endpoint during the processing of material layers in an optically hostile environment |
5722879, | Dec 06 1994 | GLOBALFOUNDRIES Inc | Variable travel carrier device and method for planarizing semiconductor wafers |
5728308, | May 26 1995 | Sony Corporation | Method of polishing a semiconductor substrate during production of a semiconductor device |
5733176, | May 24 1996 | U S BANK NATIONAL ASSOCIATION, AS COLLATERAL AGENT | Polishing pad and method of use |
5733819, | Jan 29 1996 | FUJIMI INCORPORATED | Polishing composition |
5735036, | Dec 16 1994 | International Business Machines Corporation | Lapping process for minimizing shorts and element recession at magnetic head air bearing surface |
5738562, | Jan 24 1996 | U S BANK NATIONAL ASSOCIATION, AS COLLATERAL AGENT | Apparatus and method for planar end-point detection during chemical-mechanical polishing |
5743784, | Dec 19 1995 | Applied Materials, Inc | Apparatus and method to determine the coefficient of friction of a chemical mechanical polishing pad during a pad conditioning process and to use it to control the process |
5749769, | Jun 07 1995 | MARIANA HDD B V ; HITACHI GLOBAL STORAGE TECHNOLOGIES NETHERLANDS B V | Lapping process using micro-advancement for optimizing flatness of a magnetic head air bearing surface |
5759917, | Dec 30 1996 | Cabot Microelectronics Corporation | Composition for oxide CMP |
5762537, | Aug 25 1993 | Round Rock Research, LLC | System for real-time control of semiconductor wafer polishing including heater |
5783489, | Sep 24 1996 | Cabot Microelectronics Corporation | Multi-oxidizer slurry for chemical mechanical polishing |
5830280, | Mar 15 1996 | Tokyo Electron Limited | Washing liquid for post-polishing and polishing-cleaning method in semiconductor process |
5833519, | Aug 06 1996 | U S BANK NATIONAL ASSOCIATION, AS COLLATERAL AGENT | Method and apparatus for mechanical polishing |
5842909, | Aug 25 1993 | Round Rock Research, LLC | System for real-time control of semiconductor wafer polishing including heater |
5858813, | May 10 1996 | Cabot Microelectronics Corporation | Chemical mechanical polishing slurry for metal layers and films |
5860847, | Sep 06 1995 | Ebara Corporation | Polishing apparatus |
5876266, | Jul 15 1997 | International Business Machines Corporation | Polishing pad with controlled release of desired micro-encapsulated polishing agents |
5876470, | Aug 01 1997 | Minnesota Mining and Manufacturing Company | Abrasive articles comprising a blend of abrasive particles |
5876490, | Jan 24 1997 | VERSUM MATERIALS US, LLC | Polish process and slurry for planarization |
5885137, | Jun 27 1997 | Polaris Innovations Limited | Chemical mechanical polishing pad conditioner |
5885334, | May 15 1996 | KABUSHIKI KAISHA KOBE SEIKO SHO KOBE STEEL, LTD | Polishing fluid composition and polishing method |
5906754, | Oct 21 1996 | Texas Instruments Incorporated | Apparatus integrating pad conditioner with a wafer carrier for chemical-mechanical polishing applications |
5910041, | Mar 06 1997 | Keltech Engineering | Lapping apparatus and process with raised edge on platen |
5916855, | Mar 26 1997 | GLOBALFOUNDRIES Inc | Chemical-mechanical polishing slurry formulation and method for tungsten and titanium thin films |
5919082, | Aug 22 1997 | U S BANK NATIONAL ASSOCIATION, AS COLLATERAL AGENT | Fixed abrasive polishing pad |
5934978, | Aug 15 1997 | GLOBALFOUNDRIES Inc | Methods of making and using a chemical-mechanical polishing slurry that reduces wafer defects |
5945347, | Jun 02 1995 | U S BANK NATIONAL ASSOCIATION, AS COLLATERAL AGENT | Apparatus and method for polishing a semiconductor wafer in an overhanging position |
5954975, | Nov 03 1993 | Intel Corporation | Slurries for chemical mechanical polishing tungsten films |
5954977, | Apr 19 1996 | Thermion Systems International | Method for preventing biofouling in aquatic environments |
5954997, | Dec 09 1996 | Cabot Microelectronics Corporation | Chemical mechanical polishing slurry useful for copper substrates |
5958794, | Sep 22 1995 | Minnesota Mining and Manufacturing Company | Method of modifying an exposed surface of a semiconductor wafer |
5968280, | Nov 12 1997 | JSR Corporation | Method for cleaning a surface |
5972793, | Jun 09 1997 | Vanguard International Semiconductor Corporation | Photolithography alignment mark manufacturing process in tungsten CMP metallization |
5985045, | Oct 24 1994 | SHENZHEN XINGUODU TECHNOLOGY CO , LTD | Process for polishing a semiconductor substrate |
5993298, | Mar 06 1997 | Keltech Engineering | Lapping apparatus and process with controlled liquid flow across the lapping surface |
6121143, | Sep 19 1997 | 3M Innovative Properties Company | Abrasive articles comprising a fluorochemical agent for wafer surface modification |
6257953, | Sep 25 2000 | Nevmet Corporation | Method and apparatus for controlled polishing |
6267644, | Nov 06 1998 | SemCon Tech, LLC | Fixed abrasive finishing element having aids finishing method |
6268641, | Mar 30 1998 | Kabushiki Kaisha Toshiba | Semiconductor wafer having identification indication and method of manufacturing the same |
6283829, | Nov 06 1998 | SemCon Tech, LLC | In situ friction detector method for finishing semiconductor wafers |
6291349, | Mar 25 1999 | SemCon Tech, LLC | Abrasive finishing with partial organic boundary layer |
6293851, | Nov 06 1998 | SemCon Tech, LLC | Fixed abrasive finishing method using lubricants |
WO561, | |||
WO567, | |||
WO9808919, | |||
WO9964527, |
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